further relations, which it did not have, and could not have had while those events were non-existent. This is all that ever happens to the event in question. Suppose we now ask ourselves the question: "Does anything that was true of Anne's death when it first became get false of it afterwards, through further becoming? And, if so, does this raise any logical difficulty?" Here we must draw a distinction. (1) All the relations which Anne's death entered into with the sum total of reality, as it was when this event first became, persist eternally for ever afterwards, and are wholly unaffected by anything else that may be added on to this sum total by further becoming. Hence no true proposition about these will ever become false, and no false proposition about them will ever become true. (2) As further events become they automatically enter into various relations with Anne's death, which thus acquires additional relations and becomes a constituent in additional facts. If e.g. my Lord Bolingbroke swore when he heard of Anne's death, it is clear that something subsequently became true of the death which was not true of it when it first became. When Lord Bolingbroke had sworn it became true of Queen Anne's death that it caused a certain event in his lordship's life. And this was not true of Queen Anne's death before Lord Bolingbroke had heard of it, and had thereby been caused to swear. Thus something, which was not true of Queen Anne's death when it became, is afterwards rendered true of it by the becoming of Lord Bolingbroke's oath.

Now we are inclined to think that to say that something, which was not true of an event, subsequently became true of it, is equivalent to saying that something which was false of the event, became true of it. This is, I think, a mistake; for "not-true" is a wider term than "false." Suppose we compare the two statements: "It is not true that Queen Anne's death caused the earthquake at Lisbon," and: "It is not true that Queen

Anne's death, when it happened, had caused Lord Bolingbroke to swear." In the former "not-true" is equivalent to "false." For it means that there is a certain negative fact (containing both the death and the earthquake as constituents) which discords with the judgment that the first caused the second. But the latter does not mean that at the time of Anne's death there was a negative fact, containing Anne's death and Bolingbroke's oath as constituents, and discording with the judgment that the death causes the oath. For, when Anne's death became, there was no such entity as Lord Bolingbroke's oath, and therefore no fact of which this is a constituent. What happens when Lord Bolingbroke swears is not that something which was false of Anne's death becomes true of it, but that something becomes true of Anne's death which was before neither true nor false of it.

Now I do not think that the laws of logic have anything to say against this kind of change; and, if they have, so much the worse for the laws of logic, for it is certainly a fact. What the laws of identity, contradiction, and excluded middle, between them assert is that any proposition is either true or false, cannot be both, and cannot alter in this respect. They do not assert (and, if they do, they must be amended) that the number of propositions, is eternally fixed; they only assert that it cannot be diminished. But it may be increased, and it is continually increased by the process of becoming which continually augments the sum total of existence and thereby the sum total of positive and negative facts. Or, to put it in another way, the laws of logic apply to a fixed universe of discourse, and we can at any moment get a fixed universe of discourseby taking the sum total of reality up to that moment. But the universe of actual fact is continually increasing through the becoming of fresh events; and changes in truth, which are mere increases in the number of truths through this cause, are logically unobjectionable.

I can hardly hope that what I have been saying about Time and Change will satisfy most of my readers, or indeed, that it is more than a shadow of the truth, if that. It is admitted that this is the hardest knot in the whole of philosophy. The Dean of Carlisle judiciously remarks that "we cannot understand Time, but we shall not understand it better by talking nonsense about it." In the hope that I have not darkened counsel by words without understanding, I leave this most difficult subject, to return at a later stage to the questions of one or many time series, the entanglement of Time with Space, and the placing and dating of events.

Additional works which may be consulted with profit :
B. A. W. RUSSELL, Our Knowledge of the External World,
Lecture IV.

A. N. WHITEHEAD, Concept of Nature, Cap. III.

J. M. E. M'TAGGART, The Relation of Time and Eternity (MIND, N.S., vol. xviii. No. 71).

The Unreality of Time (MIND, N.S., xvii., 1908).

H. BERGSON, Time and Free- Will.

CHAPTER III

"Its eyebrows (of a vivid green)
Have never, never yet been seen;
But Scientists, who ought to know,
Assure us that it must be so.

Oh, let us never, never doubt
What no one can be sure about!"

(H. BELLOC, The Microbe.)

The Traditional Kinematics, and its Gradual Modification in the Region of Physics. (1) The Absolute and the Relational Theories

WE have now dealt with the traditional concepts of Space and Time, and we might turn next either to Matter or to Motion. I propose to treat the classical doctrine of Motion before touching the problem of Matter. As we all know, the concept of Motion has been the subject of constant discussion by physicists and mathematicians for centuries, and in recent years the classical kinematics has been profoundly modified, owing to circumstances that have arisen within the region of Physics itself. The older arguments between supporters of Absolute and Relative Motion, and the later ones about the Theory of Relativity, are essentially pieces of Critical Philosophy in our sense of the word. Thus we may fairly say that, as regards Motion, physicists have been their own philosophers, forced into this unwelcome position by their own domestic difficulties. Now this is not so in the case of Matter. The difficulties about Matter, which show the need for radical philosophic criticism of that concept, are not indigenous to Physics itself. They arise in the main when we begin to take into account the way

too.

in which we get to know matter through sensation. It is the apparent conflict between what our sensations tell us and what Physics teaches about matter, combined with the fact that our sensations are after all the only ultimate source of all our alleged information on the subject, which compels us to indulge in philosophical criticism. The moment we begin this criticism we find that it will lead us very far afield, and that we cannot stop till we have profoundly modified the traditional concepts of Space, Time, and Motion Now I hope to be able to show that these modifications, which are forced on us as philosophers when we begin to deal with the concept of Matter, are of somewhat the same kind as those which Physicists have had to make for purely domestic reasons. If this can be shown, even in rough outline, it will greatly strengthen the case for the newer views of Space, Time, Motion, and Matter. There is much in these views which is at first sight highly paradoxical and upsetting to common-sense, so that it is of some advantage even to the scientist to know that they can be justified on wider grounds than the special needs of his science. On the other hand, it is always a comfort to the philosopher to know that he is not simply bombinans in vacuo, but is working on lines which have been found to lead to useful results in some concrete region of science.

This book is written primarily for scientists who are interested in philosophy, and secondarily for philosophers who are interested in science. It has therefore been my plan to diverge as gradually as possible from the concepts that are most familiar to scientists. Now, for the reasons given, the philosophic criticism of the concept of Motion is more familiar to most scientists than the criticism of the concept of Matter. It therefore seems right to treat the former before the latter. am going, then, to deal at present with the purely physical arguments which have gradually undermined the traditional Kinematics and replaced it by that

I