[56] [The following passage is almost word for word the same as a passage on pp. 123-5 of Mr. Russell’s Problems of Philosophy, first published in 1912, a year after Mr. R*ss*ll’s death. It is easy hastily to conclude that Mr. Russell was indebted to Mr. R*ss*ll to a greater degree than is usually supposed. But an examination of the internal evidence leads us to another conclusion. The two texts, it will be found, differ only in the names of the German Emperor, the Crown Prince and the other personages being replaced, in the book of 1912, by those of Messrs. Brown, Jones, Smith, and Robinson. Now, Mr. Russell, in a new edition of his Problems issued near the beginning of the European war and before the Russian revolution, substituted “the Emperor of Russia” for “the Emperor of China” of the first edition. Hence it seems quite likely that Mr. Russell, who has always shown a tendency to substitute existents for nonentities, wrote Mr. R*ss*ll’s notes.—Ed.]
[57] [See Chapter XLII.—Ed.]
CHAPTER XXII
THE MORTALITY OF SOCRATES
The mortality of Socrates is so often asserted in books on logic that it may be as well briefly to consider what it means. The phrase “Socrates is mortal” may be thus defined: “There is at least one instant t such that t has not to Socrates the one-many relation R which is the converse of the relation ‘exists at,’ and all instants following t have not the relation R to Socrates, and there is at least one instant t´ such that neither t´ nor any instant preceding t´ has the relation R to Socrates.”
This definition has many merits. In the first place, no assumption is made that Socrates ever lived at all. In the second place, no assumption is made that the instants of time form a continuous series. In the third place, no assumption is made as to whether Socrates had a first or last moment of his existence. If time be indeed a continuous series, then we can easily deduce[58] that there must have been either a first moment of his non-existence or a last one of his existence, but not both; just as there seems to be either a greatest weight that a man can lift or a least weight that he cannot lift, but not both.[59] This may be set forth as follows: for the present we will not concern ourselves with evidence for or against human immortality; I will merely try to present some logical questions which persistently arise whenever we think of eternal life. One of the greatest merits of modern logic is that it has allowed us to give precision to such problems, while definitely abandoning any pretensions of solving them; and I will now apply the logico-analytical method to one of the problems of our knowledge of the eternal world.[60]
We will start from the generally accepted proposition that all men are mortal. Clearly, if we could know each individual man, and know that he was mortal, that would not enable us to know that all men are mortal, unless we knew, in addition, that those were all the men there are. But we need not here assume any such knowledge of general propositions; and, though most of us will admit that the proposition in question has great intrinsic plausibility, it is not strictly necessary for our present purpose to assume anything more than the still more probable proposition “Socrates is mortal.” This last proposition, quite apart from the fact that we have a large amount of historical evidence for its truth, has been repeated so often in books on logic that it has taken on the respectable air of a platitude while preserving the character of an exceedingly probable truth. The truth also results from the fact that it is used as the conclusion of a syllogism. For it is a well-known fact that syllogisms can only be regarded as forming part of a sound education if the conclusions are obviously true. The use of a syllogism of the form “All cats are ducks and all ducks are mice, therefore all cats are mice,” would introduce grave doubts into the University of Oxford as to whether logic could any longer be considered as a valuable mental training for what are amusingly called the “learned professions.”
If, then, we divide all the instants of time, whether past, present, or future, into two series—those instants at which Socrates was alive, and those instants at which he was not alive—and leave out of consideration, for the sake of greater simplicity, all those instants before he lived, we see at once, by the simple application of Dedekind’s Axiom, that, if Socrates entered into eternal life after his death, there must have been either a last moment of his earthly life or a first moment of his eternal life, but not both.