1 Empiricism (1927)note


There has always been a certain indefiniteness about the nature of the distinctions between the different types of philosophical theory and correspondingly about the meaning of each particular “-ism”. It is obviously not an easy matter to describe a whole outlook; an attitude of mind which is felt to cover a wide range of problems cannot readily be communicated without going over all these problems. Thus it is that philosophers who disagree never seem to come to an end of their disagreements, and can hardly even understand one another. But if anything could alleviate such misunderstandings, it would be a resolute attempt to define exactly the issue or issues between different views; and this is a task which is all too seldom undertaken. It is recognised that there is a natural opposition between rationalism and empiricism, but the basis of the opposition commonly remains obscure or is wrongly stated. In briefly discussing the issue and defending empiricism I cannot hope to show exactly how this theory should be distinguished from those which go by the name of realism, naturalism, materialism, pluralism, determinism and positivism. These are all, I should argue, connected with empiricism; it is on an empiricist view, and only so, that they can be maintained. But I take empiricism as central, as giving the best general description of the philosophy which the other terms partially convey, because the issue which it raises and which it disputes with rationalism, is fundamental to logic, being concerned with truth itself. In the discussion of this issue the ways in which more detailed issues should be dealt with, will in some degree appear.

Rationalistic theories of all sorts are distinguished from empiricism by the contention that there are different kinds or degrees of truth and reality. The distinguishing-mark of empiricism as a philosophy is that it denies this, that it maintains that there is only one way of being. The issue has been confused in the past by a reference to knowledge. It was quite naturally maintained, by those who postulated different ways of being, that in relation to them different ways of knowing are required. Hence empiricism has been connected, in the history of philosophy, with the view that there is only one way of knowing, and particularly that that way is what was called “sense” in contrast to “reason”; or, rather differently, that sense is the only originator of knowledge. But

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fundamentally the issue is logical; the dispute is about ways of being or of truth, not about ways of knowing truths. It is only after it has been assumed that there are other truths than matters of fact, or that there are objects which “transcend” existence, that a special faculty has to be invented to know them.

Thus, although we naturally associate rationalism with the theory of a mental faculty of reason, the discussion of faculties will become pointless if it can be shown that any postulation of different orders of being is illogical. The same criticism will serve whether the differences are said to be of kind or of degree, since the differences of degree are to be determined in relation to a supposed highest degree, which is that of a supremely real object or Absolute. It is because objects of “higher reality” are supposed to transcend experience that the opposition to transcendentalism has the name empiricism. But if experience (by which, of course, is to be understood not our having experiences but what we experience) consists of matters of fact, then it enjoins us to reject all ideals or powers or whatever else may be contrasted with facts. Moreover, rationalistic views are contrary to experience, not merely because they set up something additional to facts, but because they set it above facts, because they make it appear that facts are somehow defective, that they are not real enough in themselves but require to be supplemented by explanations, ends or whatnot, before they can be understood or accepted by a mind.

The chief, and I think final, objection to any theory of higher and lower, or complete and incomplete, truth is that it is contrary to the very nature and possibility of discourse; that it is “unspeakable”. The empiricist, like Socrates, adopts the attitude of considering things in terms of what can be said about them, i.e., in propositions.note And he regards this not as a “second-best”, but as the only method of speaking or thinking at all, since every statement that we make, every belief that we hold, is a proposition. Since, then, the supposed higher and lower objects of experience both take the propositional form, we are concerned with a single way of being; that, namely, which is conveyed when we say that a proposition is true. Deviation from this view must take the form of saying either that facts are propositional but ideal explanations are above the propositional form, or that explanations are propositional and what they have to explain are mere data, not yet propositionalised. But in order to indicate data or ideals, we have to make statements. If there were anything either above or below the proposition, it would be beyond speech or understanding. If, for example, there were anything that required explanation before it became intelligible, we could say nothing about it in its unintelligible form; plainly, then, we could not even say that it had such a form. And, in general, it cannot be maintained either that the proposition is our way of understanding things which in themselves are not propositional, or that we have further ways of understanding the proposition which is in itself defective. Whatever

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“explanation” may be, it must at least be a relation of such a sort that what is explained and what explains it can both be stated and believed, i.e., are both propositions. But if there is no way of getting behind the proposition to something either lower or higher, we must assume that propositions can stand by themselves with nothing to supplement them, that facts need no explanation. Discourse, in fact, depends on the possibility of making separate statements, in regard to each of which the very same question can be asked — “Is it true?”

It follows that the conception of higher truths than those of fact, and that of a total truth to which all “merely particular” truths contribute, have both to be rejected. The latter view is what is currently called idealism, but since it differs from the former only in holding that there is a highest truth instead of a number of higher truths, it can be regarded as a variety of rationalism. The objection to rationalism is just that what is meant by “truth” is what is conveyed in the proposition by the copula “is”. And logically there can be no alternative to “being” and “not being”; propositions can only be true or false. There is no question, therefore, of degrees or kinds of truth; of higher and lower orders of discourse, dealing, e.g., respectively with realities and appearances. The very theory that attempts to make such a distinction has to be put forward in the form common to all discourse, it has to lay claim to the “being” signified by the copula, it has to face the direct question, “Is it true?” Thus empiricism regards it as illogical to make such distinctions as that between existence and subsistence, or between the “is” of identity, that of predication and that of membership of a class; and still more obviously illogical to say that there is something defective about “is” itself. These are all attempts to get behind the proposition, to maintain — in words! — that we mean more than we can say.

Considering propositions as they occur in discourse, we find that they can be asserted or denied, questioned, proved or disproved. In saying, then, that whatever can be asserted can be significantly denied, i.e., that there are no undeniable truths, and that whatever can be asserted or taken for granted can also be made a subject for inquiry, can be questioned or proved, i.e., that there are no unprovables, we are conveying certain characters of the common “is” of discourse (certain conditions of existence). In particular, there is no question of its indicating “necessity” as something over and above actuality. As related to other propositions any proposition has what we may, if we like, call “contingency”; but at the same time, as distinct from other propositions, as being a proposition and therefore requiring separate statement, any proposition has “absoluteness”. The forms of assertion, denial and implication being precisely the same in relation to the supposed different kinds of “is”, there is no way of establishing the difference. We can say that certain truths are of the peculiar “necessary” sort, just as we can say that no truths are “absolute”, but in both cases our speech bewrayeth us.

Rejecting in this way the distinction between necessary and other

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truths, empiricism takes up the position that in discussion or inquiry any proposition can be treated as (a) a conclusion to be proved from premises accepted, (b) a premise accepted to be used in proving some conclusion, (c) a hypothesis to be tested by the observation of the truth or falsity of the conclusions drawn from it, or (d) an observation to be used in determining the truth or falsity of conclusions drawn from a hypothesis. And if it be asked how it is determined which of these functions a proposition is to have, the empirical answer is that this is determined in discourse. Discourse depends on what the parties to it believe. If you deny what I assert, I may try to prove it by means of other propositions you admit; if we both agree on some propositions, we may set out to see what follows from them; if we are doubtful about any proposition, we may test it by its consequences. In general, discourse is possible when and only when persons come together who (a) agree about something, (b) either disagree, or wish to inquire, about something else. This position itself implies a common logic of assertion, implication and, I should add, definition. Apart from that logic, actual beliefs and observations are all that can be appealed to, and without them the process could not go on. Each of us (not excluding those who take a false view of logic) directs his inquiries and establishes his conclusions, in greater or less disagreement with others, by means of this mechanism of individual statements and particular inferences. The person who holds that there are higher truths has still to draw lower conclusions from them in the ordinary way (as it is inferred, e.g., from the “moral government of the universe” that a man is not dead after he has died); he who holds that there is a total truth can only advance towards it step by step. We have all to rely on what we find to be the case; unless we could say that a certain thing is so, we could not begin to discuss or inquire. And all this implies, I maintain, that science depends entirely on observation, i.e., on finding something to be the case, and on the use of syllogism, either for proof or for testing; or, more generally, on observation in connection with, and in distinction from, anticipation. This means that there is no distinction between empirical and rational science. Since everything that can be asserted can be denied or doubted, since deduction and hypothesis are always possible, all sciences are observational and experimental.


We may take for example the science of geometry which, like other mathematical sciences, has been regarded as “rational”. It has been commonly alleged that over and above the truths stated in geometrical theorems there are certain “first principles” of the science which in themselves are unprovable, and that the whole science follows from these principles. Leibniz has given classical expression to this position in the statement (New Essays on the Understanding, Bk. IV, Ch. I) that “it is not the figures which make the proof with geometers…It is the

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universal propositions, i.e., the definitions, the axioms, and the theorems already proved, which make the reasoning, and would maintain it even if there were no figure”. The proof of the last-mentioned theorems, of course, comes under the same general statement, and so we find that the whole science depends on axioms and definitions, supposedly identical propositions, i.e., propositions which cannot be significantly denied or conceived to be false. This position Leibniz expresses by saying that these propositions follow from “the principle of contradiction”, which therefore has embodied in it the whole of geometry and of rational science. It empowers us to reject all propositions which “involve a contradiction” and to affirm their contradictories — which neglects the fact that if a “proposition” were unintelligible, we should not know what its contradictory was.

The attempt is, in fact, to derive geometry from the notion of incompatibility or of the difference between truth and falsity. But obviously this notion could not provide us with the notion of a triangle or any other matter that geometry treats of. In order to find out that having interior angles together greater or less than two right angles is incompatible with triangularity, we require to have the specific things, triangles, before our minds. Apart from observation we could make no assertion of incompatibility whatever. To say, for example, that black is incompatible with white “because it is black” or “because it is not white” is, in either case, to presume the very thing to be proved. In demonstrating the analytic or necessary character of the proposition we surreptitiously introduce the synthetic relation, the fact. “If triangles were not X”, says the rationalist, “they would not be triangles”. Why? we ask. The only possible answer is “Because triangles are X”. The fact is required, and the “principle” adds nothing to it. We agree that in a sense the figures do not make the proof; men had known triangles long before they had raised the question of the sum of their angles. But without the figures there would be no proof, because there would be nothing to talk about. No more need be said to demonstrate the falsity of the view that geometry follows from axioms and definitions.

It is curious that, all the while that geometrical truths were regarded as having an ideal or rational character owing to their derivation from pure identities, application of them was made to physical phenomena. Yet, if they had not been synthetic, if they had not conveyed information which it was quite possible not to have about things of certain types, they could not have been applied at all. It is no answer to this argument to say that all that was required, in relation to the physical facts, was something approximately correct, something good enough for practical purposes. This is to say that geometrical truths could be treated as physical hypotheses; which would have been impossible unless there were definite points of contact between the geometrical and the physical. We could not say “Let us suppose this object to be triangular”, if triangularity were a “rational" entity and the object a “natural” one; and we could not go on to say “The object must then have certain other

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properties, and these do not differ greatly from the properties we observe it to have”, unless we could make a direct comparison between the two sets of properties. Even in supposing that a physical object has geometrical properties, we imply that there is no difference of order between physical and geometrical objects, that physical objects do fall within the field of geometry. Thus our geometrical hypotheses, or our hypothetical geometry, might actually be falsified by physical facts. If any such contradiction arose, the conclusion would not be that physical facts had failed to come up to geometrical requirements; it would be that our geometry had to be revised. The logic of application is simply the logic of syllogism; and if a geometrical theorem and a physical observation together imply the contradictory of a physical observation, we are as much entitled to question the theorem as to reject the observations. And if careful observation continues to give us the same results, we are bound to deny the theorem. This position will only appear arbitrary and out of harmony with our actual scientific procedure, to one who does not realise that our geometrical theorems are themselves the results of careful observation. But since, whether the conclusion be false or not, a theorem and a fact can together imply nothing unless they have a common term, we are bound to say that the fields of geometry and of physics are not cut off from one another, and that the two sciences are on the same empirical level. This conclusion will apply, however far “rational physics” may be carried. At some point there must be contact between “truths of fact” and “truths of reason”; as is sufficiently established by the fact that we know them both. And that which is capable of implying a fact is equally capable of being falsified by a fact.

It is on the basis of the view that geometry is hypothetical and so, by a curious perversion of the meaning of the term “hypothetical”, unaffected by fact, that the various “geometries” have been set up. Thus we are told that we can obtain different geometries according as we assert or deny Euclid's “axiom of parallels”. Now no doubt different consequences will follow from the two contradictories, but it is our business to seek for errors in these sets of consequences, in order that we may determine whether the “axiom” is true or not, i.e., whether as a matter of fact two intersecting straight lines can or cannot both be parallel to a third straight line in their plane. It is certainly a merit to have seen that Euclid's axiom can be denied, but what is then demanded will be either a testing of it by its consequences, or a deduction of it (or its contradictory) from propositions which we find to be true, or a direct statement that we find it to be true (or false). Instead of this, other propositions have been retained as axioms, and it is made a matter of choice whether we accept the proposition on parallels or not; and thus we have the various “geometries” and “spaces”. And this position is even combined with the admission that the geometries which reject the axiom have to define the straight line differently; which is really an admission that Euclid's proposition is true, and incidentally one which could not

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be made unless there were straight lines which answer to Euclid's description.

Bertrand Russell, in his Foundations of Geometry, does not make this admission; but he only avoids it by bringing in (p. 173) a reference to spherical space, in which, while “in general” it is true that there can be only one straight line between two points, in the case of antipodal points this is not so. Since the distance between such pairs bears a special relation to the constitution of the space in which they are, “it is intelligible that, for such special points, the axiom breaks down, and an infinite number of straight lines are possible between them; but unless we had started with assuming the general validity of the axiom, we could never have reached a position in which antipodal points could have been known to be peculiar”. Russell appears to use the word “general” in some private and personal sense. The natural conclusion would seem, however, to be that since the axiom is not generally valid, we have not reached a position in which antipodal points are known to be peculiar, and so no exception to Euclid's axiom has been discovered. It is also noteworthy that “unless we have started with assuming” Euclid, there would not have been terms in which to describe the “non-Euclidean” geometries and spaces. It appears to be the case that such geometries are only Euclidean geometry with different terminologies. As to the disputed proposition on parallels, it can be proved by assuming that the sum of the interior angles of a triangle is equal to two right angles. As it is employed in Euclid to prove the latter proposition, we are faced with circularity of reasoning. But the proposition on the angles of a triangle can be independently proved, if we assume that direction and difference of direction (angle) mean the same at different points; failing which there can be no question of the sum of such angles.

Waiving this point, however, we shall find it profitable to consider Russell's general argument. There are, he says (pp. 200, 201), certain “a priori axioms” which are “necessarily true of any form of externality”; but this leaves some of Euclid's “axioms”, including the proposition on parallels and that two straight lines can never enclose a space, to be “regarded as empirical laws, derived from the investigation and measurement of our actual space, and true only, as far as [the two mentioned] are concerned, within the limits set by errors of observation”. In other words, it is only by observation that we can determine whether our actual space is Euclidean or non-Euclidean. (Russell admits that we have an actual space; no doubt to save the possibility of physical applications. Nowadays this is not considered necessary, and we have the utterly illogical theory of relativity according to which nothing is “actual” and “is” has no meaning.) But there are still the a priori axioms (axioms proper) which are not empirical laws but are necessarily true of any form of externality. In considering this position we have to ask how, except by observation of actual externality, we discover what is true of it or what is “deducible from the fact that a science of spatial magnitude is possible (p. 175); how this deduction proceeds, so as to enable us to

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distinguish what is true of experienced space and what is necessary to any form of externality; how, in fact, we can distinguish in space those characters which make it external from its other characters. Russell wishes to show that there are, or may be, forms of externality which, having certain characters of the form which we have observed, do not have others. But in order to show this he must point to forms which do not have the latter characters. If space is the only form of externality that we know, then all the forms that we know have all the characters of space. In order to distinguish characters which are essential to externality from others which are accidental, we shall have to say that in the case of the former we can “see the connection” and as regards the latter see that there is no connection. In other words, necessary connections between some of its attributes and necessary disconnections between others are among the characters of space. To justify this conclusion it would have to be said that we had grasped by a single act of thought all the characters of externality in general and of our actual space in particular. Such a position ignores the possibility of discovery and the nature of deduction.

The question is, then, in what way the view that “all forms of externality are X, Y, Z” but “some possible forms of externality are not A, B, C”, i.e., are not Euclidean, can be supported. X, Y, Z, the a priori axioms, are supposed to follow from “analysis” of externality. But this analysis can only proceed by simply finding certain characteristics of externality. If analysis were taken to show the necessity of these characteristics, then this necessity in turn would be a characteristic which was simply found. In short, Russell's “deduction”, which is supposed to demonstrate necessity, can only start from, and proceed in terms of, observation of actuality. Similarly when he says (p. 62) that “those properties [of the form of externality] which can be deduced from its mere function of rendering experience of interrelated diversity possible, are to be regarded as a priori”, his position is quite illogical. The properties of interrelated diversity can be discovered only by examining situations which exhibit interrelated diversity; so that not only are the premises and the conclusions of the supposed deductions identical (viz., all things which render experience of interrelated diversity possible are X, Y, Z), but nothing is said to show that Euclid's axioms are not equally “a priori”, since Euclid claims that they indicate properties which he finds in such situations, i.e., in the only interrelated diversity he knows. In fact, the question is solely of “empirical laws”. This is partly obscured, not only by the reference to “deduction”, but also by the reference to “experience” of interrelated diversity. But all the propositions in question are about what is diverse and interrelated, and nothing about experiencing really enters into the argument.

Russell makes a great point of the “logical consistency” of non-Euclidean systems. Here again he is assuming that he knows “all about” such systems, or that he has the peculiar privilege of declaring what is to be regarded as assailable and what is unassailable. We have to note

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two distinct senses in which consistency and inconsistency are spoken of. There is inconsistency in fact; two propositions are said to be inconsistent when one, with a fact or a number of facts, implies the falsity of the other, i.e., when the two together, with or without certain facts, imply a false proposition. This cannot be determined by taking the propositions by themselves but only in relation to facts. But two propositions, inconsistent in this sense, may be perfectly consistent in the other sense, viz., that neither by itself implies the falsity of the other. Now consistency in the latter sense is of the very slightest importance as a description of a group of propositions. Limiting ourselves to that group we find no member of it disproved by any other or collection of others. But there is nothing scientific about limiting ourselves to such a group, allowing them to “define” a science. We ought, on the contrary, to bring them into relation with every available fact, so that any real inconsistency will appear. Russell cannot say that both Euclidean and non-Euclidean geometries are consistent in the broader sense; so that the consistency he claims for non-Euclidean geometry is a barren distinction.

We conclude, then, that geometry is, like all others, an empirical or experimental science dealing with things of a certain sort, that there is nothing “a priori” about it but that it is concerned throughout with fact. When Russell says (Principles of Mathematics, p. 5) that pure mathematics asserts “merely that Euclidean propositions follow from the Euclidean axioms, i.e., it asserts an implication; any space which has such and such properties has also such and such other properties”, he is again using “implication” in his characteristically loose way, and he omits to indicate that these facts can be discovered only if we can examine a space having “such and such properties”. Geometry, we may say, is concerned with empirical characters and relations of things in space and is a practical science, and Euclidean geometry consists not of “implications” but of propositions (connected to some extent, of course, by argument) which are either true or false. We can say that, if there were no externality, no geometrical propositions would be true, just as we can say that if there were no distinction between truth and falsity, no propositions whatever would be true. But these statements do not help us in the least to discover any proposition, geometrical or other, which is true. To call them, therefore, statements of the implications of the form of externality and of the principle of contradiction is the sheerest absurdity. We must rather say that, since these “principles” have no practical consequences, there are no such principles. Our sole concern in science is with facts, and we can attach no meaning to the suppositions “if there were no externality” and “if there were no distinction between truth and falsity”; they cannot even be conceived to be facts, that is, they cannot be supposed.


We have found that the conditions of discourse and inquiry demand the rejection of “pure” science and the assertion that all sciences deal

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with facts, in relation to which we assert or deny, prove or suppose. We have found, in other words, that the theory of different ways of being is untenable. But with it falls the theory of different ways of knowing, the distinction between sense and reason. The very slightly empiricist character of the work of those philosophers who are called “the English empiricists” is accounted for by their still making this very unempirical distinction. In maintaining that all our knowledge is derived from sense (a position which, on account of their rationalist preconceptions, they by no means maintained consistently) they took a view of sense which was dependent on its having been regarded as an inferior way of knowing. It was supposed to provide isolated data, materials which reason had to shape into, or subordinate to, the coherent system of knowledge which we call science. And Hume, while admitting that no such coherence could be imposed upon isolated data, still maintained that the data of sense were isolated, and accordingly could not show how science is possible. The rejoinder of idealists like Green that Hume's position leaves out of account the function of the mind as a relating agency, that it takes as real what has not yet been made real by the work of the mind, is no reply. Hume's argument is precisely that neither mind nor any other agency could possibly perform such work on “distinct existences”. And this is the point of departure of the “radical empiricism” of James. Mind is not required to relate things, because things are given as related just as much as they are given as distinguished. Connections and distinctions, in fact, are given together; and those who argue that the work of the mind is required to connect distinct things, might equally well maintain that work had previously been required to distinguish them. Here James is drawing attention to the important fact (important, as well as for other reasons, in view of the persistent misunderstanding of the meaning of empiricism) that there is nothing in the least empirical in the conception of a “distinct existence”. It is on the contrary the rationalist conception of “essence” masquerading as a fact of experience.

If, then, there is to be any question of what is given or presented (though it would be better to speak of what is observed), connections must be included. This is in line with the view already set forth that what can be contemplated or enunciated is always in the form of a proposition; in other words, that we always deal with complex states of affairs and never with “simple entities”. Any theory which refers to the work of the mind, or to rational factors, as contributing, along with sensible or given factors, to making things intelligible, is self-refuting or “unspeakable”. If whatever is intelligible has both connections and distinctions, then in order to speak intelligibly of what is contributed by the mind we shall have to assume that it has both connections and distinctions, and in order to speak intelligibly of what is given by things we shall have to assume that it has both connections and distinctions, so that no “work of the mind” is required to make it intelligible. And in the same way, in speaking intelligibly of “knowledge”, we are speaking of a certain state of affairs, the mental process which knows, as connected

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with and distinguished from another state of affairs, the process or situation, mental or non-mental, which is known.

We cannot, then, make any such distinction as between “things as we know them” and “things themselves”. Unless the former are things themselves, we are not entitled to speak of things (and hence to speak) at all. On the other hand, we are entitled to reject, by reference to things themselves, viz., the things we know, any suggestion of an agency whose operation cannot be detected; which we cannot observe acting on some observed situation and bringing about observable changes therein. As “rational factors”, ex hypothesi, cannot be seen at work (since they must have worked before anything can be seen; since they are “conditions of the possibility of experience”), not only can we not assert that there are such ideal entities, but we cannot show what they would do, if there were. An agency whose presence cannot be detected is an agency which it is of no advantage to postulate, as Berkeley showed in regard to Locke's “matter”. We cannot have a “merely inferential” knowledge of it. We must be able to say: “This is the sort of thing which under certain circumstances will act in such and such a way, and under other circumstances will act in a different way”. But if we have never observed it so acting, if we have never been able to distinguish it from its effects on the situation, then the whole content of our knowledge, all that we are in a position to speak about, consists of the circumstances, no longer to be described as effects of “it”, at least. The appeal to inference, or to the distinction between “knowledge by acquaintance” and “knowledge by description”, is futile. We can say, for example, that any man we happen to meet had parents; we can have an indirect knowledge of their existence, though we have never seen them. But this would not have been possible if we had not at some time known individuals who stood in that relation to some one, and had not thereafter come to believe that all beings of a certain sort have parents. We cannot, then, by inference from what we observe, conclude that there is a mind whose function it is to observe these things, i.e., which is purely instrumental, a pure agency. Unless we have observed minds, we cannot speak of them. Having observed them, and having observed that they are related by “knowledge” to other things, we can also consider how they fall into error. But this criticism of the mind's operation in regard to things cannot take the form of “criticism of the instrument”. We cannot, without self-refutation, undertake to criticise the mind's entire knowledge; for it is by our knowledge that we criticise. Criticism, then, can only proceed by our asserting what we find to be the case; we can criticise propositions only by means of propositions, similarly asserted. The distinction of ways of knowing, at least in the form of a distinction among faculties, is therefore untenable. We can, of course, distinguish such attitudes as asserting and supposing. But in every case we are dealing with something which is, or may be, found to be the case, and there is no question of seeking for and fostering some superior instrument.

In terms of this theory it must be said that in psychology, and

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likewise in ethics, our knowledge is observational and propositional. The question is of psychological and ethical facts, and not of an ultimate agency or ultimate standards. These sciences, like all others, are nothing if not empirical and experimental. This does not, of course, mean that minds must be studied in a laboratory; they show some of their characteristics better in other social situations. Love, for example, is a very important psychical phenomenon; in fact it may be said that no one can know much about minds who has not taken it into account. But none but the most hardened “experimentalist” will claim that a laboratory is the best place for getting to know its characters and conditions. The main point is that, in order to know minds, we have to observe them and think about them. There is no real distinction between thinking and experiment. In each we require some hypothesis, and in each case we test it by reference to what we believe, or find, to be the case, i.e., by whether or not its consequences are in accordance with facts which we know. In holding that in order to know minds we have to look at them, empiricism is not opposed to “introspection”, the study of our own minds, though it opposes the supposition that in this peculiar case the process which knows and the process which is known are identical; i.e., it insists on the fact that the study of our own minds takes place by means of observation. But, an empiricist will say, there is no more reason for confining ourselves to “introspection” than for considering only our own bodies in studying physiology.

What has chiefly to be emphasised, however, is that the observation of minds, the knowledge of them in propositions, requires the rejection of the “unitary” view of mind. the conception of it as having only one character and being self-contained in that character. This is a rationalist, “unspeakable” view. If we are to have any dealings with minds, we must be able to consider how they act in different situations, i.e., to consider them as having complex characters and activities, as being divisible and determinate. Psychological science will only be possible if we have a variety of psychological truths, between which, and in each of which, connection and distinction are discernible. And the same applies to ethics. These sciences are historical, they are studies of occurrences and activities, they are concerned with situations in space and time. I have thus, without going into detail, indicated the place in the empiricist scheme of the other anti-rationalist theories I mentioned. The general conclusion is that all the objects of science, including minds and goods, are things occurring in space and time (the only reason for regarding minds as not in space being the rationalistic contention that they are indivisible), and that we can study them by virtue of the fact that we come into spatial and temporal relations with them. And therefore all ideals, ultimates, symbols, agencies and the like are to be rejected, and no such distinction as that of facts and principles, or facts and values, can be maintained. There are only facts, i.e., occurrences in space and time.