garded as unbroken, and are mental phenomena to be looked upon as the invariable concomitants of certain physical changes; or are the two classes of facts to be built into the one series? Those who accept the first alternative are parallelists, and those who accept the second are interactionists.
Naturally, there is a lively quarrel between the two sects. The parallelist insists that the interactionist has no clear notion of what he means by interaction, when he uses the word; and he maintains that, did the interactionist realize his position, he would see himself to be little better than a materialist. He has failed to recognize the great distinction between mental phenomena and physical. On the other hand, the interactionist insists that the parallelist, in declaring the series of physical changes to be unbroken, has reduced the mind to a position of utter insignificance. Every action can be accounted for by going back to its physical causes, and to those alone. The mind, then, is a mere decoration; it does nothing; the man is a physical automaton, etc., etc.
I am not going to try to persuade any one, in this paper, to become an adherent of either the one sect or the other. But it does seem rather hard that those who watch the combat should be led to suppose that, with the triumph of the one party, they are condemned to become materialists, and, with the triumph of the other, they are turned into automata. It is distressing to be confronted with Scylla and Charybdis, and to see no clear water between.
What I wish to prove is that the whole matter is one to be regarded with no other emotion than that of intellectual curiosity; and that it does not matter a particle to the plain man, from the practical point of view, which side wins.
First let us assume that the interactionist is right. Then ideas and motions in matter may be regarded as belonging to the one series— they are links in the one chain. Now, one can not piece out a defective series of sounds by the insertion of a smell; one can not, when one tree in an avenue has died, replace it by a tree in a dream. To constitute a series, in any significant sense of the word, things must have something in common; it must mean something to speak of gaps and insertions. Let us suppose, for the sake of argument, that it does mean something here, and that ideas are enough like motions in matter to be inserted between certain motions in matter and to form one series with them.
This may be a form of materialism; but what of that? The man whose day has been full of ideas, of desires and volitions, of plans and purposes, has had just the day that he has had; and the fact that all these are called material or semi-material does not prevent their being just what he has experienced them to be. If some material things can