they would still remain perfectly unintelligible. Astronomical knowledge of the brain—the highest grade of knowledge we can expect ever to have—discloses to us nothing but matter in motion. But we cannot, by means of any imaginable movement of material particles, bridge over the chasm between the conscious and the unconscious.
Motion can only produce motion, or be converted back into potential energy. Potential energy can only produce motion, maintain static equilibrium, or exert pressure or traction. The sum of energy, however, remains the same. Beyond this law nothing can go in the physical world, nor can any thing fall short of it; the mechanical cause passes completely into the mechanical effect. Hence the mental phenomena, which in the brain appear in company with material phenomena, are, so far as our understanding is concerned, void of sufficient basis. They lie beyond the law of causality, and hence are unintelligible, like a mobile perpetuum. But they are also unintelligible on other grounds.
True, on superficial observation, it looks as though certain mental operations and conditions might be intelligible to us, from a knowledge of the material phenomena of the brain. Among such mental phenomena I might reckon memory, association of ideas, habit, specific talents, etc. It needs but little reflection to show that this is an error. We should only be acquainted with certain inner conditions of the soul's life, which are of about equal import with the external conditions created by sense-impressions; but we should know nothing about the origin of mental life in virtue of these conditions.
What conceivable connection subsists between definite movements of definite atoms in my brain, on the one hand, and on the other hand such (for me) primordial, indefinable, undeniable facts as these: "I feel pain, or pleasure; I experience a sweet taste, or smell a rose, or hear an organ, or see something red," and the immediately-consequent certainty, "Therefore I exist?" It is absolutely and forever inconceivable that a number of carbon, hydrogen, nitrogen, oxygen, etc., atoms should not be indifferent as to their own position and motion, past, present, or future. It is utterly inconceivable how consciousness should result from their joint action. If their respective positions and their motion were not indifferent to them, they would have to be regarded as each possessed of a consciousness of its own, and as so many monads. But this would not explain consciousness in general, nor would it in the least assist us in understanding the unitary consciousness of the individual.
That it is and ever will remain utterly impossible to understand higher mental operations from the mechanics of the cerebral atoms (supposing them to be known), needs not to be proved. Yet, as has been already remarked, we need not consider the higher forms of mental activity, in order to add weight to our argument. But its force is intensified by contrasting the absolute ignorance wherein astronomical