Introduction.

The aim of the Tarner Benefaction is to found a course of lectures on "the relation or lack of relation between the various sciences." Dr Whitehead, who gave the first course, dealt with applied geometry and chronometry, dynamics, and the Theory of Relativity. He left to his immediate successor a delicate and invidious task. Dr Whitehead's Concept of Nature is an epoch-making book by a man who is a complete master of the technical part of his subject and an original philosophic thinker of the highest order. Taken in conjunction with its predecessor, The Principles of Natural Knowledge, and its sequel, The Principle of Relativity, it forms the most important contribution which has been made for many years to the philosophy of mathematical physics. For me to attempt to cover the same ground again in these lectures would be to expose myself to the most unflattering comparisons. Moreover, I have lately dealt with these matters to the best of my ability in my Scientific Thought; and, whilst I am well aware how much room there is for improvement in that book, my readers must be as tired of seeing my views on this subject as I am at present of writing them down. I therefore determined to choose a problem which should be supplementary to Dr Whitehead's work and should overlap it as little as possible.

Now the limitations which the first Tarner Lecturer deliberately imposed on himself at once suggest a subject for discussion by his immediate successor. He quite explicitly confined himself to the study of Nature as an object of Mind. He refused to complicate his problem by dealing with the stuff and structure of mind as such, or with its place within the physical world which it contemplates and acts upon. And, beside this, Dr Whitehead confined himself to the most general characteristics of the physical world, to those which are shared by stones, trees, and animal or human bodies. He did not consider in detail the very great apparent differences which there are between such objects as these. In these self-imposed limitations he was, I think, wholly justified. The problem of the external world as such is a terribly hard one, and it has certainly been made harder in the past by being mixed up to a needless extent with psychological and physiological questions. I found it necessary to follow much the same course, so far as I could, in my Scientific Thought. Nevertheless, it seems clear to me (and I do not suppose that Dr Whitehead would seriously dissent) that all sharp divisions of Reality into water-tight compartments, and all confinement of our attention to the common characteristics of things which also differ profoundly, are practically necessary rather than theoretically satisfactory. Minds do arise, to all appearance, within the physical world; and they do remain, to all appearance, tightly bound to certain special physical objects, viz., living animal organisms. And, having arisen and being connected with such organisms, they do then proceed to perceive, think about, act upon, feel emotions toward, and approve or disapprove of things and events in the physical world. Nor do they confine their attention to such objects. A mind may perform all these acts towards itself and towards other minds as well as towards physical things and events; and the minds which we know most about are concerned almost as much with themselves and with other minds as with matter. Nor does even this exhaust the objects with which minds are apparently concerned from time to time. Some minds, and especially Dr Whitehead's, seem to spend a good deal of their time in contemplating, reasoning about, and feeling approval or disapproval towards objects which are, on the face of them, neither material nor mental, e.g., numbers, propositions, and the formal relations of such objects among themselves. And it is certainly arguable that a mind could go little if any distance in cognising objects which are physical or mental if it did not have the power of cognising objects which are neither.

Now these are vitally important facts which must presumably shed some further light on the stuff and structure of the world as a whole, and even on that part of it which consists of physical things and processes and is called "Nature." When we treat any one part of Reality in isolation from the rest, or when we concentrate on the common features of things which also differ profoundly, it is certain that our results will not be the whole truth and probable that they will not be wholly true. The speculative philosopher and the scientific specialist are liable to two opposite mistakes. The former tends to deliver frontal attacks on Reality as a whole, armed only with a few wide general principles, and to neglect to isolate and master in detail particular problems. The latter tends to forget that he has violently abstracted one part or one aspect of Reality from the rest, and to imagine that the success which this abstraction has given him within a limited field justifies him in taking the principles which hold therein as the whole truth about the whole world. The one cannot see the trees for the wood, and the other cannot see the wood for the trees. The result of both kinds of mistake is the same, viz., to produce philosophical theories which may be self-consistent but which must be described as "silly". By a "silly" theory I mean one which may be held at the time when one is talking or writing professionally, but which only an inmate of a lunatic asylum would think of carrying into daily life. I should count Behaviourism, taken quite strictly, and certain forms of Idealism as "silly" in this sense. No one in his senses can in practice regard himself or his friends or enemies simply as ingenious machines produced by other machines, or can regard his arm-chair or his poker as being literally societies of spirits or thoughts in the mind of God. It must not be supposed that the men who maintain these theories and believe that they believe them are "silly" people. Only very acute and learned men could have thought of anything so odd or defended anything so preposterous against the continual protests of common-sense.

General Remarks on Method.

In view of these dangers it seems to me that the best plan for the philosopher is somewhat as follows. He must start by considering separately those departments of Reality which seem prima facie to be susceptible of fairly elaborate treatment by themselves without detailed knowledge of their relations to each other. He must then analyse and reflect upon each of these in turn as carefully and exhaustively as he can until he finds himself nearing a point at which no further progress can be made in understanding one without a detailed study of its relations to the others. In the meanwhile he will always bear in mind that the departments which he is treating separately are in fact connected with each other, and that any results which he has reached about one of them will probably need some correction and modification when he takes into account those relations with the rest which he has hitherto been ignoring. Again, within each department he will begin by considering those most abstract and pervasive features which are common to all things that fall within it and so exhibit its general structure and ground-plan. When he has done this he will pass on to consider the most striking and apparently fundamental differences between different objects which fall into the same department. Here again he will do well to remember that the study of the detailed differences may force him to modify his original conclusions about the common structure of the department in question. Thus the general procedure is (1) gradually to work forward from the parts to the whole and from the common features of each part to the characteristic differences within it; and (2) at every stage to look back on one's earlier results and see how far and in what direction they need to be modified in the light of the later ones.

Now it might be objected at this stage that the suggested method prejudges the question of Pluralism or Monism. I do not think that it does. The plain fact is that if the world be too much or too little of a unity there is not the least chance of our ever being able to understand it. If it were as pluralistic as Leibniz thought or as monistic as Mr Bradley seems to have believed, I do not see how knowledge would be possible. What we find is that Reality as a whole does seem to show a mixture of unity and relative isolation; and it is reasonable to begin with the departments which seem relatively independent and work at them in detail before considering the connexions which they undoubtedly also have with each other. So long as we know what we are doing, and clearly recognise that what seems at first sight closely connected may prove to be separable and that what seems at first sight independent may prove to be intimately connected, we shall not go far wrong.

I have said that at each stage of our work we must look back to see whether the results of the earlier stages need correction or modification. I want now to explain this possibility a little further. In the first place, the results of our earlier and more abstract investigations may be seen to be positively wrong in some respects when we take into account the more special and concrete aspects of Reality which we had formerly been ignoring. But there is a second alternative which may arise if we have been lucky in our original division of Reality into separate departments and cautious in the statement of our conclusions about these departments. We may find, in this case, that we have not positively to correct anything that we have already asserted, but have only to choose between alternatives which we have already recognised as possible. So long as we confine ourselves to each department in isolation from the rest, and so long as we investigate only the general ground-plan of each department, we may well find that a number of alternative theories are open to us and that we have no means of deciding between them. As we go on to consider the relations of one department to the others and the detailed differences within each department, we may find that this new knowledge favours certain of these alternatives and excludes others. In that event we shall not be correcting past errors, but merely replacing true but less determinate theories by true and more determinate theories. This is of course the ideal path of philosophic progress; but we cannot assume that we shall strike it. Our chance of doing so depends partly on initial luck and insight in our division of the subject-matter, and partly on the power of recognising a number of alternatives and not thinking at any stage that our knowledge is more determinate than it really is.

I will now illustrate my meaning with an example. In Dr Whitehead's Lectures and in my Scientific Thought we are concerned with matter only as known to the physicist, and with mind only as something which perceives and thinks about matter. The main problem at that level is to state clearly what is meant by "sensible appearance", and to reconcile what we know about the sensible appearances and their qualities and mutual relations with what physics asserts about the matter which appears to us in this way. Now it seems to me that, so long as we confine ourselves to these data, many alternative theories about the nature of matter and of mind are possible. But, in the first place, we have to remember that matter seems to have differences of kind within it beside the common features which are studied by the mathematical physicist. E.g., there seem to be a number of ddifferent chemical elements; there seems to be a fundamental difference between living organisms and inorganic matter; and so on. Again, within the region of mind there are apparently very profound differences. Oysters, perhaps, can only feel; cats, perhaps, can only feel and perceive; men can feel, perceive and reason; and so on. Secondly, we have to notice that there is in fact a most intimate relation between minds and living bodies. The minds that we know about are not disembodied spirits; they seem to be tied to organisms, to grow and decay with these, and to cease when these die. Moreover, in our part of the world at any rate, there seems to have been a gradual historic development of mind going hand in hand with a growth in the complexity of living matter. Any theory of Reality which can claim to be even approximately adequate must take such apparent facts into account, and must contain a doctrine of matter and mind which shall be consistent with them. Now it may well be that, of the various theories which were possible when we considered merely the common properties of mind and of matter and when we looked on mind merely as a contemplator of matter, some will be ruled out when we take account of the different sorts of mind and of matter and the apparent relation of dependence between these two departments of Reality. And it may be that some of the remaining alternatives will be better adapted than others to this new and more concrete situation.

I propose therefore to consider in these lectures the Mind and its Place in Nature. As minds are specially closely connected with those peculiar bodies called "animal organisms" I shall also have to consider the apparent differences between living and non-living matter. This line of inquiry seems to fall quite naturally into the scheme of the Tarner Benefaction; for it amounts to considering the "relation or want of relation" between physics, physiology, and psychology. I shall in certain places assume that the reader is acquainted with my Scientific Thought; but I shall take no special pains to make the outcome of this inquiry square with the outcome of that. If they should turn out to be mutually consistent, so much the better. But I shall follow my argument whithersoever it may lead; and, if fragments of my works should survive the downfall which Western civilisation is so busily preparing for itself, it will perhaps be the pleasing task of the Negro commentators of the future universities of central Africa to excogitate a consistent system of thought from my scattered remains.

I propose to attack the problem in the following order. (A) I shall begin by taking quite traditional and commonplace views about matter and mind, and shall discuss at that level the old questions of Mechanism and Vitalism and of the Relation of Mind and Body. (B) Next I shall consider critically the sources of our alleged knowledge of Matter, of our own Minds, and of other Minds. In this section I shall also discuss Memory, which is involved in all our knowledge. This should enable us to decide how much we are probably justified in asserting about the nature of Matter and of Mind, taken in isolation from each other. (C) it will then be profitable to say something about what seem to be common features of living organisms and minds, or to be on the borderline between merely vital and obviously mental phenomena. I allude here to Mnemic Phenomena and the "Unconscious". At the end of this section we shall see that there are certain alternative possibilities between which we cannot decide unless we know whether minds ever survive the destruction of the organisms which they have animated. Therefore (D) I then proceed to discuss the arguments for and against human survival of bodiIy death. Finally (E) I shall consider the internal unity of the mind, and its position and probable prospects in Nature.

Dangers of the Genetic Method. In dealing with living organisms and with minds there is a complication which does not arise to the same extent in considering nonliving matter. This is the fact of evolution. Each mind and each organism that we know of has developed gradually from very simple beginnings. And, again, there is some reason to think that the most complex minds and organisms which have appeared up to a given date are less and less complex as that date is pushed further back in the earth's history, and that the more complex organisms of later date are the descendants of less complex organisms of earlier date. However this may be, it is certain that at the present time there are minds and organisms of very various degrees of complexity, ranging from amoebas through cats and dogs to men. Now, in trying to analyse and understand any complex state of affairs which has gradually grown up from simpler beginnings, there are two alternative orders of treatment. One is to start by considering the most perfect and highly developed instances of the phenomenon in question. Another is to treat the problem genetically, devoting great attention to its earliest, simplest, and crudest forms. The latter is of course the more popular order at the present time. My own view is that neither line of approach can be dispensed with, but that the former is the more fundamental of the two. In the first place, if we want to study the nature and structure of some important item in Reality it is surely more sensible to begin by studying it in its most characteristic and developed forms than in those elementary beginnings in which it is barely distinguishable from other factors in Reality. Even if one's main interest be in the development of something it is at least as important to know what it has developed into as what it has developed out of. Secondly, if we start from the other end, we are liable to fall into two errors. (a) We are extremely likely to underestimate the complexity and ignore the peculiarities of the final stage, because we cannot see how they could have developed out of the earlier and simpler stages. It certainly seems to me that evolutionary accounts of Mind very often fail altogether to take due account of the most characteristic features of the most highly developed minds. Now it is much more disastrous to slur over differences which are really irreducible than to recognise differences and wrongly think them to be irreducible. If we make the latter error we still have in hand all the data for the solution of our problem, and we or others will solve it when we have pushed our analysis a little further. But, if we make the former mistake, our data are incomplete and the problem cannot possibly be solved until we have recognised this fact. My first objection then to starting from the lower end and working to the higher is that this way of approach tends to prevent one from viewing the latter with an unprejudiced eye, and to make one commit the greatest of all mistakes in philosophy, that of ever-simplifying the facts to be explained.

(b) A second danger is the following. When I study the evolution of anything, be it an animal or an institution or a mental process, I am simply learning about the history of it and its "ancestors " in a wide sense of that word. I learn that A developed into B, B into C, and C into the thing in question. Now we are all extremely liable to confuse a history of the becoming of a thing with an analysis of the thing as it has become. Because C arose out of B, and B out of A, people are inclined to think that C is nothing but A in a disguised form. Thus, suppose we could show that action from a sense of duty developed out of action from fear of public opinion, that this developed out of action from fear of the ghosts of dead ancestors, and that this developed out of action from fear of living chiefs. All that we should really have done would be to give a history of the process of becoming which ended in action from a sense of duty. But we should be very liable to think that we had analysed the sense of duty as it now exists, and proved that it is just a disguised form of fear of punishment by tribal chiefs. This would be simply a gross mistake. To analyse anything you must examine and reflect upon it, and the most elaborate account of what preceded it in the course of history is no substitute for this. At the best a study of the history of a thing may make you look for factors in the thing which you might otherwise have missed. But, on the other hand, as I have already pointed out, it is just as likely to make you turn a blind eye to factors in it which were not present in the earlier stages. And, in any case, you have no right whatever to say that the end is just the beginning in disguise if, on inspecting the end as carefully and fairly as you can, you do not detect the characteristics of the beginning in it and do detect characteristics which were not present in the beginning.

There is a certain kind of pretentious futility which is closely connected with this error and is highly typical of some of the sillier psycho-analysts. Suppose we are told that a taste for music is due to suppressed sexual desire or to Dr Ernest Jones's family pet, "infantile anal-erotic sensations". What is the precise cash-value of such a statement? It cannot mean that this is a sufficient condition of a taste for music, since the psycho-analyst would be the first to assure us that suppressed sexual desire can exist in people who show no taste for music but an excessive fondness for pet animals. Thus other factors must be needed to account for the taste for music in one person and the mania for keeping cats in the other. And these other factors will plainly be the more characteristic cause-factors, since the suppressed sexual desire is supposed to be the common condition of both, whilst the other factors determine which of the two shall result. So the most that can be said is that the suppressed sexual desire is a necessary condition of a taste for music. Now it is obvious that the more different states the psycho-analyst ascribes to suppressed sexual desire the more trivial his statement becomes about any one of them. If this desire be a necessary condition of fifty different tastes, accomplishments, diseases, and crotchets, it is of extremely little interest to say of any one of them that it is "due to" suppressed sexual desire. It is about as useful as to say that committing a murder is "due to" being born. This is true, since you could not commit a murder without having been born. But it is not very interesting or important, since it is equally true that being born is a necessary condition of saving another man's life at the risk of your own.

Thus, one characteristic mistake of the incautious user of the genetic method is to give a rather trivial necessary condition of some highly developed state as if it were the sufficient condition. He then proceeds to ignore the other conditions, which are equally necessary and much more characteristic. The next move is to confuse a list of the historical conditions out of which a thing arose with an analysis of the thing itself. And so, from the perfectly trivial, even if true, proposition that suppressed sexual desire is a necessary condition of a taste for music, he jumps by these two steps to the interesting but extremely doubtful assertion that a taste for music is just a disguised form of sexual desire. For these reasons I think I am justified in the order which I propose to adopt, i.e., in discussing the apparent features of highly developed minds at an early stage, and not considering the borderline of instinct and the unconscious until later. And perhaps it is relevant to add that I fancy I can imagine what it feels like to be a highly developed mind much better than l can imagine what it feels like to be a flea or an amoeba. But, of course, that may just be my conceit.

Value of the Abnormal. Before leaving this subject I must make one further remark about method, which may seem to be inconsistent with what I have just been saying but is not, I think, really so. I hold that it is of the utmost value for the philosopher to study the abnormal in all subjects. E.g., it is such facts as dreams, hallucination, mirror-images, etc., which prevent (or should prevent) us from taking too simple-minded a view of the external world and our perception of it. If we start with a theory made to fit the normal cases alone, we shall probably never be able to square the abnormal cases with it. If, on the other hand, we take the abnormal cases into account from the very first, we may be able to devise a general theory which covers both them and the normal cases. The normal cases may then be seen to arise from the fulfilment of certain special conditions which do in fact generally hold, but which do not hold of necessity and are not in fact fulfilled in the abnormal cases. A simple example from mathematics will make this clear. If we had started by confining our attention to circles, and had then insisted on regarding all other conic-sections as circles which had more or less "gone to the bad", it seems unlikely that we should ever have had a very satisfactory theory of conic-sections. The alternative and much better plan is to start with the general equation of a conic-section, and to see that circles, ellipses, hyperbolas, etc., are special cases which arise through special values of, or special relations between, the co-efficients in this general equation.

Now this general principle is just as important in considering minds as it is in considering the external world and our perception of it. This fact may be illustrated in three ways. (1) If we study sane human beings in their waking moments we find a very high degree of unity in their minds. And, if we confine ourselves to them, we shall be tempted to think that psychical events can exist only as states of selves, and that each human body can have only one self connected with it. Now these conclusions may be true; but they begin to look much less plausible when we consider abnormal phenomena, such as automatic writing, multiple personality, etc. Moreover, a study of such phenomena may lead us to scrutinise more carefully the normal human mind, and we may then find that even the mind of a healty young Scotsman "on the make" is a good deal less unified than it seemed to be. In the end we may decide that the facts as a whole are best explained by supposing that psychical events need not be states of selves and that one human body need not be connected with only one self. The considerable degree of mental unity which we find as a rule, and the normal assignment of one self to one body, may then be regarded as due to the fulfilment of certain special conditions which generally hold but need not and some times do not. It will still be a most important fact that these conditions tend to be approximately fulfilled in the vast majority of cases, so that there will be no excuse for neglecting the study of normal minds. But the study of the abnormal will have had two excellent effects. It will have presented alternative hypotheses to us which we should otherwise not have contemplated as possible, and it will have made us notice certain facts about the normal mind which we should otherwise not have looked for. (2) Under normal circumstances one mind seems to be incapable of knowing what is going on in another except by listening to the speech or watching the gestures of the body with which this other mind is connected. Most theories of mind assume that this very roundabout method is the only possible way in which one mind can communicate with another. Now it seems to me that the existence of telepathy between specially sensitive subjects and between ordinary minds under special conditions has been firmly established by the work of the S.P.R., and I consider that I have met with undoubted instances of it in sittings which I have had with the medium Mrs Osborne Leonard. The establishment of such facts opens up many possibilities which would otherwise have had to be rejected, and it suggests that even in normal human intercourse a telepathic factor may play some part. (3) Lastly, there are the more debatable cases in which it looks as if a human mind were communicating after the death of its body. At present it would be very unwise to philosophise about the mind with such cases mainly in view. But it seems to me to be almost equally rash to put forward a theory of mind and its relation to body which totally ignores these phenomena and assumes that they can all be explained away.

Now I do not think that there is any inconsistency between my present contention that philosophy must attend most carefully to the abnormal and my former assertion that it must start by considering the most highly developed, and therefore the most characteristic, minds and mental processes. In the first place, many of the phenomena dealt with by Psychical Research may be fairly regarded as supernormal, i.e., as instances in which a mind shows powers which no mind was suspected of having. And, even in the merely pathological abnormalities which the psycho-analyst and the student of multiple personality treat, we are concerned with derangements which can happen only to a mind of a fairly high order. We should not expect to find multiple personality in a guinea-pig or suppressed complexes in an amoeba; a mind must be fairly highly developed before it can go wrong in an interesting and instructive way.

Pluralism and Monism.

I have now said all that I want to say about method. In doing so, however, I have introduced the notion of Reality falling into relatively isolated, though connected, "departments". I have also talked of apparently fundamental differences of kind among things which belong to the same department. To explain these notions further it will be necessary to say something about the traditional antithesis of "Pluralism" and "Monism". These words are terribly ambiguous, and I think it will be both useful and relevant to clear up their ambiguities at this stage. In doing so I shall be throwing some light on the principles which I have been asserting, shall sketch out the possible alternatives which have to be considered in detail in later chapters, and shall show something of the conditions on which the "connexion or lack of connexion of the various sciences" depends.

Existents and Abstracta. The first great division within Reality as a whole which strikes one is the distinction between the part which exists and the part which is real but not existent. The contents of the latter I call "Abstracta". The names "Pluralism" and "Monism" are usually confined to different views about the nature of the Existent; but a prior question arises, for some philosophers have held that the difference between Abstracta and Existents is not ultimate, since in their view there are no Abstracta. A Nominalist, who holds that there are no universals but only words used in a certain way, would be a Monist, in a sense in which a Realist, who holds that there are real universals whether ante rem or only in re, would not. However, we have the words "Realist", in the mediaeval sense, and "Anti-Realist" (covering Nominalists and Conceptualists) to mark this distinction; and we can therefore keep the words "Monist" and "Pluralist" for differences of opinion about the Existent. Nevertheless, I will briefly explain what I understand by the distinction, which seems to me to be a real and irreducible one.

I do not think that "Existence" can be defined, but I think that it can be unambiguously described. (a) Whatever exists can occur in a proposition only as a logical subject. Of course the name of an existent may appear in a sentence as a grammatical object and in other positions too. E.g., in the sentence "Smith dislikes Jones" the only grammatical subject is the word "Smith", and the word "Jones" counts as a grammatical object. Nevertheless, the men Smith and Jones are both logical subjects of the proposition for which this sentence stands. This property, however, cannot safely be taken by itself to mark out existents. If there be such entities as propositions they are certainly Abstracta and not Existents; yet it would seem that the only part which one proposition can play in another proposition is that of logical subject. E.g., if the sentence "Edwin will marry Angelina" stands for a single complex entity, a proposition, then it can only appear in such other propositions as: it is probable that Edwin will marry Angelina, or: Smith believes that Edwin will marry Angelina. And in these secondary propositions it is plain that the original proposition about Edwin and Angelina is present as a logical subject. (b) A second characteristic which belongs to all Existents and to no Abstracta is that they are either literally and directly in time; or, if time be unreal, have those characteristics, whatever they may be, which make them appear to human minds to be directly and literally in time. I put the matter in this way because, although I see no reason to doubt the reality of time, there are philosophers who deny it and yet believe that there are existents. If then I had said that all existents are literally and directly in time I should have prejudged this question. But I think that even those philosophers who deny the reality of time would accept the second part of the above alternative.

I do not think that Abstracta can even be unambiguously described except by saying that that they are real but non-existent. But they can be indicated enumeratively. This class of realities includes qualities, relations, numbers, and also propositions and classes if there be such entities. Abstracta of course do not exist, and neither are nor appear to be literally and directly in time. But some at least of them are very closely connected with existents, and thereby become indirectly connected with time. This happens in two different ways. (a) Certain qualities characterise certain things or events from time to time. Again, certain relations relate now one set of existents and now another. And many propositions are about things and events which exist in time. (b) Any Abstractum may from time to time become the object of someone's thought. The proposition that Charles I was beheaded is not in time directly and literally, as Charles I and the axe are; but it is connected indirectly with time, both because it is about temporal things and events and because I began to think of it a moment ago and shall cease to think of it a few minutes hence. All that can happen to a quality is that it sometimes characterises one, sometimes another, and sometimes perhaps no existent; and that it is sometimes thought of by me, sometimes by you, and sometimes perhaps by no one The realm of Abstracta, as such, forms the inexhaustible subject-matter of the a priori sciences of Pure Logic and Pure Mathematics.

On this matter, which it would be irrelevant to pursue further here, 1 am certainly a Realist to the extent of accepting universalia in re as absolutely irreducible factors in Reality. And I am inclined to be a Realist in the stronger sense of believing that we cannot do without universalia ante rem, i.e., simple and unanalysable universals which will never have instances. But I think it possible that we may be able to devise a means of dispensing with such universals, though I do not at present see how to do the trick.

Pluralism and Monism about the Existent. -- I will first illustrate the ambiguities of these terms by taking examples. (1) Leibniz is commonly counted as a typical pluralist. And in one sense he certainly was. Descartes is commonly regarded as a typical dualist. But, in the sense in which Descartes is a dualist, Leibniz is a monist. Leibniz held that all that appears as matter is really mind, whilst Descartes held that mind and matter are equally real and quite irreducible to other. We therefore say that Leibniz was a monist in the sense in which Descartes was a dualist. But Leibniz was equally certain that there is a very large number of minds, each of which is an independent substance; and in this Descartes agreed with him. In this sense they were both pluralists. Let us next consider the case of Spinoza, who is commonly regarded as a typical monist. In the sense in which Leibniz was a monist, and Descartes was a dualist, Spinoza was an extreme Pluralist. For he not only held that thought and extension were both real and mutually irreducible; he held that these were just two out of an infinite number of equally real and mutually irreducible "Attributes". On the other hand, Spinoza was a monist in the sense in which Leibniz was a pluralist. He held that minds are not independent substances but are simply "modes" of the "attribute" of thought; and he meant roughly by this that there is a single psychic continuant of which all minds are merely occurrent states. Of course he held a similar view about bodies. In this sense Descartes was a pluralist about mind and a monist about matter, for he agreed with Leibniz that minds are continuants and with Spinoza that bodies are occurrents.

These examples illustrate some, but not all, of the ambiguities. Let us imagine two materialists who both believed that there are many independent material particles. So far they would both be monists, in the sense in which Leibniz is and Spinoza is not a monist. And they would both be pluralists, in the sense in which Leibniz is and Spinoza is not a pluralist. Now let us suppose that one of these materialists holds that there is a plurality of irreducibly different kinds of material particle, e.g., Oxygen atoms, Hydrogen atoms, and so on. And let us suppose that the other thinks that there is ultimately only one kind of material particle, and that the differences between Oxygen, Hydrogen, etc., are simply differences in the structure and movements of different groups of these particles. Then the second materialist would be a monist in a certain sense. And, in this sense, the first materialist would be a pluralist. Lebniz was a pluralist in this sense; for he held that there were ultimately different orders of mind, e.g., "bare monads", the souls of animals, and human minds.

Let us now try to draw the necessary distinctions and to define our terms. (a) There are certain attributes which anything must have if it is to be a substance at all. I should say that anything that is a substance must have some duration and must be capable of standing in causal relations. Or, since some people deny the reality of time and of causation, let us say that anything that is a substance must have those characteristics, whatever they may be, which appear to human minds as duration and causation. I will call these "Substantial Attributes". There are other attributes which need not have in order to be a substance. It need not be extended and it need not even appear to be so. Again, it need not have the power of feeling or cognising, and it need not even seem to have this.

(b) Now it must be admitted that every actual substance must have some special attribute or other beside the substantial attributes which are essential to all substances. This special attribute will make it a substance of such and such a kind, e.g., a material or a mental substance. Let us call such attributes "Differentiating Attributes". It will be necessary to describe the nature of a differentiating attribute a little more fully. (1) It must not be essential to substance as such, even if in fact it be possessed by all substances. E.g., if materialism be true, extension is an attribute which is in fact possessed by all substances. But it is a differentiating attribute for all that, since it is not essential for a substance as such to be extended. (2) It is a determinable which is not itself a determinate under any higher determinable. This condition is needed for the following reason. Suppose that the properties of being gold, being silver, and so on, are ultimate and irreducible. We do not want to count these as differentiating attributes; but, if we did not add the present condition, it is difficult to see why we should not have to do so. But these properties would be determinates under the higher determinable "matter", and so they will not have to be counted as differentiating attributes if we add the condition that such attributes must be determinables of the highest order. (3) If it belongs to any complex substance as a whole it must belong also to all its parts. This has to be added in view of the doctrine of "emergent qualities", about which more will be said in what follows. An emergent quality is roughly a quality which belongs to a complex as a whole and not to its parts. Some people hold that life and consciousness are emergent qualities of material aggregates of a certain kind and degree of complexity. If there be such qualities we do not want to have to count them as differentiating attributes. (4) It must be a simple attribute, i.e., it must not be analysable into a conjunction or disjunction of other attributes.

We can now define the first kind of Pluralism and Monism. This I will call "Pluralism and Monism about Differentiating Attributes". A " Differentiating Attribute Monist" holds that there is in fact only one differentiating attribute. Materialists, like Hobbes, and Mentalists, like Leibniz, are monists of this kind. A "Differentiating-Attribute Pluralist" holds that there are two or more differentiating attributes. Pluralists of this kind can be further subdivided according to two different principles. (1) We may take the trivial principle of dividing them according to the number of differentiating attributes which they accept. E.g., Descartes was a dualist and accepted two only; Spinoza accepted an infinite number; and there seems no obvious reason why there should not be Trialists or Hendekalists in this sense, though I cannot call any to mind at the moment. (2) A much more important principle of division is the following. Some people who accept a plurality of differentiating attributes hold that one and the same substance can have several or all of these attributes. Thus Spinoza held that God has all the infinite number of differentiating attributes. Others consider the various differentiating attributes to be incompatible with each other. This view was held by Descartes of the two differentiating attributes which he accepted. The first kind of differentiating-attribute pluralist can (though he need not) believe that there is only one substance, as Spinoza did. The second kind of differentiating-attribute pluralist must admit at least as many different substances as there are differentiating attributes, and he may of course admit more. Descartes could not consistently have accepted less than two substances; and in fact he accepted a great many more, since he thought that each individual mind is a distinct substance. On the other hand, a man can be a differentiating-attribute monist, like Leibniz, and yet accept an infinite plurality of substances.

We have now to consider a second meaning of the antithesis between Pluralism and Monism. Just as every actual substance has some differentiating attribute as well as the substantial attributes, so too every actual substance has its differentiating attribute in some specific form. No material substance is just a bit of matter; it has the Oxygen properties, or the Hydrogen properties, or the Silver Chloride properties, and so on. Similarly, no mind is just a thinking substance; it has the characteristic properties of an oyster's mind, or of a dog's, or of a man's, or of an angel's, and so on. I will call these more specific features, which distinguish different "natural kinds" of substances having the same differentiating attribute, "Specific Properties". And I will call the aggregate of substances which have a common differentiating attribute, taken together, a "Realm of Being". E.g., we can talk of the "Mental Realm" and the "Material Realm". The question can then be raised: "Are there several ultimately different kinds of substance within a single realm of being, or are all the apparently different specific properties within a realm of being really reducible to a single one? E.g., must the Oxygen-property and the Hydrogen-property simply be accepted as ultimate; or can they both be derived from certain common properties of all matter, such as extension, spatial arrangement, motion of particles, etc.?" We might call a man who accepted the first alternative a "Pluralist about the Specific Properties of Matter", and one who accepted the second alternative a "Monist about the Specific Properties of Matter". It would of course be quite consistent to be a differentiating-attribute pluralist and a specific-property monist about some or all of the realms of being. And the opposite combination of views would also be quite consistent. E.g., Leibniz was a differentiating-attribute monist; but he was a specific-property pluralist, since he believed in ulttmately different kids of mind. Descartes, on the other hand, was a differentiating-attribute dualist. But he was a specific-propertv monist about the realm of matter, for he thought that the apparently different kinds of matter differ only in the arrangement and parts of a single homogeneous substance. He was a specific-property pluralist about the realm of mind, for he certainly held that God's mind differs in kind from human minds. It is evident that, if a man believes in a plurality of kinds of substance within a single realm of being, he must accept at least as great a plurality of substances, and he may of course accept a much greater plurality of substances than of kinds.

This brings us to a third sense of "Monism" and "Pluralism". On the face of it there can be a plurality of substances having the same specific properties. E.g., it is plainly true, in some sense, that there is a large number of human minds and a large number of hydrogen atoms in the universe. Now some men hold that the minds of Smith, Brown, Jones, and Robinson actually are distinct and independent substances; others hold that they are not strictly substances at all, but only states of a single substance. Similarly, some men hold that atoms or electrons are not strictly substances; but are merely different states of vortex-motion in a single substance, the ether. We might call the former class of people "Substantival Pluralists" and the latter class "Substantival Monists". Spinoza and Mr Bradley are examples of substantival monists; for both of them regard chairs and tables and minds, not as substances, but as "modifications", "differentiations", or "states" of a single Substance. But, whereas Spinoza is an extreme pluralist about differentiating attributes, Mr Bradley is a differentiating-attribute monist; for he thinks that the Absolute consists wholly of mental stuff or "experience", as he calls it.

Let us now sum up the results of this attempt at clarification. We have distinguished and exemplified three different kinds of opposition under the vague disjunction of Pluralism and Monism. (i) Differentiating-attribute Pluralism and Monism. This kind of pluralism may take two forms (apart altogether from the question of how many differentiating attributes are accepted). (a) It may allow that the differentiating attributes are all compatible with each other; in which case it is consistent with, though it does not entail, Substantival Monism. (b) it may deny the compatibility of some or of all combinations of differentiating attributes, in which case it entails some degree at any rate of Substantival Pluralism. (ii) Specific-Property Pluralism and Monism. This is the question whether there are or are not irreducibly different kinds of substance within the same realm of being, i.e., with the same differentiating attributes. Monism about differentiating attributes is compatible with pluralism about specific properties (cf. Leibniz); and pluralism about differentiating attributes is compatible with monism about specific properties in some or in all realms of being (cf. Descartes' view of matter). Specific-property Monism is consistent with, but does not entail, Substantival Monism. Specific-property Pluralism does entail some degree at any rate of Substantival Pluralism. (iii) Substantival Pluralism and Monism. This is the question whether the apparent plurality of substances of the same kind is really a plurality of substances or only of the states or occurrents of a single Substance. As we have seen, Substantival Monism is not entailed by either of the other kinds of monism, but some degree of Substantival Pluralism is entailed by each of the other forms of pluralism. And, just as it is possible to be a Specific-property Monist for one realm of being and a Specific-property Pluralist for another realm, so it is possible to be a Substantival Monist for one realm and a Substantival Pluralist for another (cf. Descartes' views on Matter and Mind respectively).

Pluralism and Monism about Differentiating Attributes will be discussed in Section E of this book. Pluralism and Monism about Specific Properties in the realm of matter will be discussed in the next chapter. But I may not have another opportunity of saying anything about Substantival Monism and Pluralism, so l will end this chapter with some remarks about this antithesis.

The controversy between Substantival Monists and Pluralists seems to me to be partly verbal, and to depend on taking the word "substance" in a wider or a narrower sense. Suppose we define a substance simply as a particular existence, which is practically what Dr M'Taggart does. Then twinges of toothache, flashes of lightning, and so on, must be counted as substances. For they certainly exist or appear to exist literally in time, and they cannot occupy any position in a proposition except that of logical subject. But most people would refuse to call them "substances". They would call such objects "events in" or "states of" substances. Evidently these people mean by a "substance" something more specific than a particular existent. They would say that all substances are converse is not true. It is no very easy to say exactly what more is needed. One feature that seems to be assumed is that a substance must last for a considerable time. In fact, whatever else it may be, it would seem that it is supposed to be at least a series of events having a certain kind of internal unity and continuity both causal and spatio-temporal, and lasting at least long enough for this unity to be fully manifest. I think that it is also assumed by most people that all events which do not themselves last long enough to count as substances are parts of some series of interconnected events which is a substance.

It will be seen that, under these circumstances, the distinction between a substance and a mere event is likely to be hard to draw in practice, and that a certain particular existent will be asserted to be a substance by some and denied to be a substance by others. Moreover, we must notice that, when two things are very closely interconnected, some people would call them "two substances" whilst others would call the whole which they together form "one substance". E.g., we generally think of a man's body as a single substance, though, from another point of view, his head is one substance and his trunk is another. Bearing these facts in mind, let us compare the ordinary view of the world as consisting of a plurality of substances with the view of a typical Substantival Monist, such as Spinoza. The ordinary man would count the various chairs in his room as so many distinct substances; and he would take the same view about his own and his neighbours' minds. But he probably would not count the falling of a chair or a passing twinge of toothache as substances; he would say that they are only states or modifications of substances. And he would say this partly because they are so transitory, and partly because he thinks that they could not have existed by themselves; e.g., that a fall can exist only as part of the history of some body, and that a feeling of toothache can exist only as part of the history of some mind. The plain man thus takes long duration, and the possibility of independent existence, as marks of a substance; and he takes transitoriness and incapacity for independent existence as marks of a mere state or modification of a substance.

Now it is very easy for a Substantival Monist to attack this position. How long must a particular last in order to count as a substance? The plain man says that a flash of lihhtning or a twinge of toothache is too transitory to be a substance, but holds that a human body lasts long enough to be a substance. But this is obviously rather arbitrary. The duration of a human body is very small as compared with that of the pyramids and almost negligible as compared with that of a mountain. Thus, if the distinction is to turn on mere duration, it seems difficult to find any safe resting-place between the two extreme views of Dr M'Taggart and of Spinoza, viz., that every particular existent, however transitory, is a substance, and that no existent can count as a substance unless it be eternal.

The common-sense view does not fare very much better if we take the capacity for independent existence as the characteristic mark of a substance. No doubt it is extremely difficult to conceive of a perfectly isolated twinge of toothache, forming no part of a longer and wider whole, called a "mind ". But is it much easier to conceive the existence of a perfectly isolated human body, when you clearly understand what you are trying to do? Eating, breathing, sleeping, walking, etc., are all characteristic features of a living human body; and it is hard to see how anything with these properties could be conceived to exist without air to breathe, ground to walk on, and so on. Thus the radical distinction which common-sense draws between the twinge of toothache, as a mere state incapable of independent existence, and the human body as a genuine substance capable of existing independently, seems rather arbitrary on reflection. A Substantival Monist, like Spinoza, would meet the difficulty by saying that no finite particulars are capable of independent existence and that therefore none of them deserves the name of "substance". According to this view, nothing less than the whole material world throughout Space and Time would deserve the name of "substance ". All finite bodies are merely states or modifications of this, which last for longer or shorter times and then break up, giving place to other modifications.

Probably many people would be ready to accept this mode of statement as on the whole the best way of expressing the known facts about the material realm. Perhaps we might, however, put the case somewhat differently. We might hold that, whilst the difference between a substantive and an adjective is a difference of kind, that between substances and states is a matter of degree. Anyone who held Substantival Monism to mean that chairs or minds are literally adjectives, i.e., universals and not particulars, would plainly be talking nonsense. It is plain that the proposition: John Smith exists, does not mean: The Universe has a John-Smithy character, for this is either meaningless or false. It must be admitted that some Monists have talked as if they meant to assert some such nonsense as this; but it is charitable to suppose that they were merely expressing themselves badly. The difference between an adjective and a substantive is that between a universal and a particular, and it is irreducible. On the other hand, what would commonly be called a "substance" and what would commonly be called a "mere state" are both particulars. Now I would suggest that it is quite reasonable to talk of "degrees of substantiality". Cæteris paribus, an existent is more of a substance the longer it lasts and the less dependent it is on anything else. I should then agree with Spinoza to the following extent. I should say that the solar system is much more substantial than my body; and that my body is much more substantial than a sneeze; and that the whole material world, if it forms a single self-contained physical system, is still more of a substance than the solar system. So far I should agree with the more reasonable Substantival Monists, though I should state the facts in rather different language.

But, although the question at issue is thus largely verbal, it is not wholly so. There are three closely connected points to be noticed which are not merely verbal. (1) Spinoza took a similar view about mind to that which I have just been stating in my own way about matter. He held that finite minds are not ggenuine substances any more than finite bodies; they are just states or modifications of a single mind-substance. (He would have said "mind-attribute", but for the present purpose there is no important distinction between what Spinoza calls an "attribute" and what I am calling a "substance".) Now I can accept the negative part of this statement tentatively, but I see very little reason to accept the positive part. I think it is perfectly true that finite minds have a comparatively low degree of substantiality, unless they are very different from what they appear in this life to be. No doubt my mind is more substantial than a twinge of toothache. But, in the first place, it apparently begins and ends in time. Again, it is apparently not existing during large parts of the time between my birth and my death. Lastly, it seems to be extremely dependent on my body. These appearances may of course be deceptive; we shall have to consider the question in greater detail in a future chapter. But I think we may fairly say that a human mind, taken at its face-value, is a poor sort of substance.

So far I should agree with Spinoza. But l cannot see much reason to think that there is anything mental which is more substantial than finite minds, poor things as they are; or that finite minds are states of some one mental substance which is more substantial than themselves. The material realm does seem to form one single system in a fairly definite sense. All finite bodies have spatial relations to each other, and all physical events are causally interconnected by gravitation and other forces which bridge the spatio-temporal gaps between them. Moreover, the whole seems to be of much the same nature as the parts. The spatial and causal relations within a finite body and between its parts are of much the same nature as the spatial and causal relations between two finite bodies and within the material realm as a whole. Now, so far as one can see, there is very little analogy to this within the mental realm. No doubt some groups of minds form societies which last longer than any of their individual members; and probably all human minds do belong to such societies. I think it would be perfectly correct to call Trinity College or the Judicial Committee of the Privy Council a "mental substance". But we must remember (a) that a society is in many ways less substantial than the minds which compose it; (b) that it is not a mental substance, in the sense that it is a mind, but only in the sense that its constituents are minds. A society of minds is not a big mind; but a system of bodies (such as the solar system) is just a big body; (c) there is no one society which includes all minds; and (d) the minds which are included in any one society are also as a rule included in others which are not parts of the first. The essential point is that the relations within a mind and between its states seem to be different in kind from the relations between several minds and within a society, and that no society is at once all-inclusive and very highly unified. I therefore can see no good ground for believing in a single mental substance of which all finite minds could be regarded as states or modifications. I think that this notion would become plausible only if we had reason to believe that all minds are in some kind of intimate telepathic union, analogous to gravitation in the material realm, and that the system thus formed was itself of the nature of a mind.

(2) The second qualification that must be made to my tentative acceptance of a form of Substantival Monism is this. I have granted that the typical material substances of ordinary life, viz., human bodies, chairs, trees, etc., are only imperfectly substantial, since they are transitory and incapable of existing in isolation. And I have granted that the solar system, and still more the whole material realm, can claim a higher degree of substantiality. But might we not say that some things which are much smaller than the material substances of daily life, viz., molecules, atoms, electrons, etc., can claim a very high degree of substantiality? If this be so, we could not agree with Spinoza in holding that only the material realm as a whole deserves to be called a material substance; we should have to hold that there are also certain parts of the material realm which have just as good claims to this name. And I think that this must be admitted. We took endurance and capacity for independent existence as two tests for substantiality. Now a thing may be enduring and self-subsistent for two different reasons. (a) It may be so because it is so very inclusive. The solar system is more enduring and self-subsistent than my body because there is so very little outside it to upset it. (b) A thing may not include very much, but it may be extremely stable. This may happen in two different ways. (i) It may be that, although there are many things outside it, it is indifferent to nearly all of them, so that they have no hold on it. (ii) It may be that, although it is influenced by other things, it has an intense degree of internal unity and can be destroyed by these things only under very special circumstances which very seldom arise. Now it seems to be a fact that, as you divide up the material realm in Space and Time, there are certain definite stages of division below which disintegrating forces which were formerly effective cease to be so, e.g., a chair can be broken up by many means, including an axe. A molecule cannot be split up by mechanical means, but it can be by heat or chemical reagents. The ordinary atoms are so stable that only heroic methods will break them up. I should say that, at the stages of molecules, atoms, and electrons, we come across genuine natural units each of which may fairly claim a high degree of substantiality.

(3) There is one other remark to be made. We have said that the notion of a substance involves the persistence of something through a lapse of time, and that the longer this something persists the more substantial it is said to be. But common-sense distinguishes between the mere persistence of form and the persistence of stuff. We can identify a certain ripple on a sheet of water and follow it as it moves along just as well as we can identify a certain speck of dust and follow it as it rests or moves through the air. But the persistence of the ripple is known to be just the fact that a certain kind of movement successively affects a continuous series of different particles of water; whilst the persistence of the speck of dust is the fact that the same bit of stuff occupies successively the same or a continuous series of successive places. Now it is commonly held that the two kinds of persistence are essentially different; and that things which have the latter kind are substances, whilst those which have only the former are not. On this view, if an electron could be shown to be merely a persistent vortex in the ether it would be denied to be a substance, even though it could be shown that such a vortex must go on for ever. For, it would be said, an electron on this theory fails to fulfil the second condition of substantiality. From the nature of the case a vortex in the ether could not exist without the ether existing to move in whirlpools, but the ether: could quite well have existed without moving in this or any other way. Hence the ether is the only genuine substance concerned, and the electrons would be counted merely as states, though endless and indestructible states, of the ether.

I doubt whether this sharp distinction between substances and mere states, based on the difference between the two kinds of persistence, can be upheld. (i) We must notice that there are border-line cases in which there is persistence of form with gradual change of stuff. Here common-sense does not hesitate to hold that we have a persistent substance. A human body is a fairly obvious instance. No doubt at two moments near together the bulk of the stuff of which it is composed is the same; but there is always some difference, and we all know that after a few years scarcely any of the same stuff remains. Yet, if the outward form and the characteristic ways of behaving are kept, no one hesitates to call it the same body or attempts to deny that it is a substance. (ii) Common-sense presumably regards a mind as a persistent substance; yet it may fairly be doubted whether in this case there is anything corresponding to the notion of persistent stuff. (iii) These, however, are merely examples of the fact that common-sense is not perfectly consistent in practice, which we all knew before. The important question is whether there is really any fundamental difference between persistence of stuff and persistence of form. If this distinction can be got rid off, it must be by reducing persistence of stuff to persistence of form, I think. Let us consider the case of what would be called "the same bit of stuff" resting for a time in one place and then moving to another. We must first distinguish between its purely spatial properties, i.e., its shape and size at any moment, and what I will call its "material qualities," i.e., its colour, weight, chemical and physical constants, and so on. Now, if the persistence of this bit of stuff is to be reduced to persistence of form, in a wide sense, this reduction must be made somewhat as follows. We should have to say that all that is meant by the persistence of a certain bit of stuff is that certain determinable characteristics are manifested throughout a period of time in one or in a continuous series of determinate forms throughout one or a continuous series of places.

This attempted reduction of persistence of stuff to persistence of form seems most plausible when we confine our attention to solid bodies with sharp outlines which rest or move about in vacuo or in a fluid medium markedly different from themselves. It is much less plausible when we try to apply it to a homogeneous fluid. Imagine a homogeneous incompressible fluid with no solid bodies in it. Let us consider a small volume at any place within this fluid. Then, whether the fluid were wholly at rest or there were currents steadily circulating within it, precisely the same properties would continue to be manifested throughout the small volume that we have chosen for investigation. On the principles suggested above we should have to say in both cases that this volume contains a single persistent bit of stuff. But actually we always distinguish in theory the two cases (a) where the constancy of the properties manifested in any small volume is due to the fluid being at rest, so that nothing is flowing into or out of this volume; and (b) where this constancy is due to the fact that the fluid is in a steady state of internal motion, and the matter which flows into the volume is always exactly like the matter which it displaces therefrom. Since we plainly do distinguish these two cases in thought, even if we cannot always distinguish them in practice, it would seem that the attempted reduction of persistence of stuff to persistence of form has failed. (Of course it would be quite easy to distinguish the two cases in practice as well as in theory if we put a drop of highly coloured liquid into our fluid and saw whether the colour merely diffused slowly and equally in all directions or streamed out in one direction.)

I am inclined to think that there is a more ultimate objection than this, which applies as much to the attempted reduction for solids as to its application to homogeneous fluids. It seems to me that the theory in question presupposes the existence of Absolute Space, in a quite crude and literal sense. When it is said that certain properties continue to pervade "the same place", or that they successively pervade "a continuous series of different places", we presuppose the existence and persistence of these places. We are in fact thinking of Space as a kind of persistent homogeneous medium, which differs from the homogeneous-fluid ether only in the fact that it has nothing but spatial properties and that all its parts are eternally at rest. And we are thinking of the material properties as being manifested now in one part and now in another of this medium. But this just amounts to saying that the stuff of all material substances is Space. We shall still have to distinguish between a plurality of different bits of stuff, for each different volume in Space will now be a different bit of stuff. We have thus not got rid of the notion of stuff, nor dissolved persistence of stuff into persistence of form, nor avoided the necessity of accepting a plurality of different bits of stuff. The difference between this view and the more usual one is not that the former avoids the notion of stuff altogether whilst the latter uses it. The real differences are these. (a) On the present view no bit of stuff can move about; and the motion of a body becomes the successive inherence of the same or a continuous series of determinate qualities in a continuous series of different bits of stuff; whilst, on the more usual view, bits of stuff themselves move about. And (b) on the present view the various bits of stuff are just different volumes within a single continuum; whilst, on the more usual view, the various bits of stuff are not all in contact with each other at any time. The former type of theory, as I have said, requires Absolute Space, in the literal substantival sense; whilst the latter fits in with a Relational Theory of Space. But neither can do without the notion of stuff or without accepting a plurality of different bits of stuff; since Absolute Space becomes the stuff of the former theory, and the different parts of Absolute Space become the plurality of different bits of stuff.

My conclusion then is that in the long run we cannot be Substantival Monists about the material realm. For, if it be true that Absolute Space would be one substance and that space is the only kind of stuff in the material world, it is equally true that every part of Absolute Space is a distinct substance, so that there will be as many bits of stuff as there are different spaces within Absolute Space. The differences between a hydro-dynamic and an atomic view of the material world are no doubt important; but it is a mistake to think that they are differences about Substantival Monism or Pluralism. For, as I have tried to show, both types of view presuppose Substantival Pluralism, though at different places. Really the question at issue between them is whether there is one kind of material stuff or many; and this is the question of Specific-Property Monism or Pluralism.

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Contents -- Go to Chapter II

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