One more matter remains to be touched upon in this section.  It has doubtless been observed that Mill, in the extract given above, seems to place “feelings,” in other words, mental phenomena, between one set of bodily motions and another.  He makes them the middle link in a chain whose first and third links are material.  The parallelist cannot treat mind in this way.  He claims that to make mental phenomena effects or causes of bodily motions is to make them material.

Must, then, the parallelist abandon the argument for other minds?  Not at all.  The force of the argument lies in interpreting the phenomena presented by other bodies as one knows by experience the phenomena of one’s own body must be interpreted.  He who concludes that the relation between his own mind and his own body can best be described as a “parallelism,” must judge that other men’s minds are related to their bodies in the same way.  He must treat his neighbor as he treats himself.  The argument from analogy remains the same.

42.  WHAT OTHER MINDS ARE THERE?—­That other men have minds nobody really doubts, as we have seen above.  They resemble us so closely, their actions are so analogous to our own, that, although we sometimes give ourselves a good deal of trouble to ascertain what sort of minds they have, we never think of asking ourselves whether they have minds.

Nor does it ever occur to the man who owns a dog, or who drives a horse, to ask himself whether the creature has a mind.  He may complain that it has not much of a mind, or he may marvel at its intelligence—­his attitude will depend upon the expectations which he has been led to form.  But regard the animal as he would regard a bicycle or an automobile, he will not.  The brute is not precisely like us, but its actions bear an unmistakable analogy to our own; pleasure and pain, hope and fear, desire and aversion, are so plainly to be read into them that we feel that a man must be “high gravel blind” not to see their significance.

Nevertheless, it has been possible for man, under the prepossession of a mistaken philosophical theory, to assume the whole brute creation to be without consciousness.  When Descartes had learned something of the mechanism of the human body, and had placed the human soul—­hospes comesque corporis—­in the little pineal gland in the midst of the brain, the conception in his mind was not unlike that which we have when we picture to ourselves a locomotive engine with an engineer in its cab.  The man gives intelligent direction; but, under some circumstances, the machine can do a good deal in the absence of the man; if it is started, it can run of itself, and to do this, it must go through a series of complicated motions.