Second:  If it is desirable to avoid the word “cause,” in speaking of the relation of the mental and the physical, on the ground that otherwise we give the word a double sense, why is it not desirable to avoid the word “concomitance”?  Have we not seen that the word is ambiguous?  I admit the inconsistency and plead in excuse only that I have chosen the lesser of two evils.  It is fatally easy to slip into the error of thinking of the mind as though it were material and had a place in the physical world.  In using the word “concomitance” I enter a protest against this.  But I have, of course, no right to use it without showing just what kind of concomitance I mean.

[1] “First and Fundamental Truths,” Book I, Part II, Chapter II.  New York, 1889.

[2] “Lectures and Essays,” Vol.  II, p. 57.  London, 1879.

CHAPTER X

HOW WE KNOW THERE ARE OTHER MINDS

40.  IS IT CERTAIN THAT WE KNOW IT?—­I suppose there is no man in his sober senses who seriously believes that no other mind than his own exists.  There is, to be sure, an imaginary being more or less discussed by those interested in philosophy, a creature called the Solipsist, who is credited with this doctrine.  But men do not become solipsists, though they certainly say things now and then that other men think logically lead to some such unnatural view of things; and more rarely they say things that sound as if the speaker, in some moods, at least, might actually harbor such a view.

Thus the philosopher Fichte (1762-1814) talks in certain of his writings as though he believed himself to be the universe, and his words cause Jean Paul Richter, the inimitable, to break out in his characteristic way:  “The very worst of it all is the lazy, aimless, aristocratic, insular life that a god must lead; he has no one to go with.  If I am not to sit still for all time and eternity, if I let myself down as well as I can and make myself finite, that I may have something in the way of society, still I have, like petty princes, only my own creatures to echo my words. . . .  Every being, even the highest Being, wishes something to love and to honor.  But the Fichtean doctrine that I am my own body-maker leaves me with nothing whatever—­with not so much as the beggar’s dog or the prisoner’s spider. . . .  Truly I wish that there were men, and that I were one of them. . . .  If there exists, as I very much fear, no one but myself, unlucky dog that I am, then there is no one at such a pass as I.”

Just how much Fichte’s words meant to the man who wrote them may be a matter for dispute.  Certainly no one has shown a greater moral earnestness or a greater regard for his fellowmen than this philosopher, and we must not hastily accuse any one of being a solipsist.  But that to certain men, and, indeed, to many men, there have come thoughts that have seemed to point in this direction—­that not a few have had doubts as to their ability to prove the existence of other minds—­this we must admit.