Page:Popular Science Monthly Volume 5.djvu/41

From Wikisource
Jump to: navigation, search
This page has been validated.
31
LIMITS OF OUR KNOWLEDGE OF NATURE.

looked the fourth and simplest supposition, viz., that perhaps the watches, whose simultaneous action is to be accounted for, may be after all only one. Whether we shall ever understand mental phenomena from their material conditions is a very different question from that other, viz., whether these phenomena are the product of material conditions. The former question might be decided in the negative without in the least affecting the latter, to say nothing of negativing it.

In the passage we have already cited, Leibnitz asserts that a mind incomparably higher than the human mind, but yet finite, could, if it were possessed of senses and technical powers of like perfection, form a body capable of mimicking the actions of man. He does not say that a man could be formed, for in his view the automaton of flesh and bone, which he regards as soulless, even as Descartes regarded all animals, still lacks the mechanically-incomprehensible soul-monad. The difference between Leibnitz's point of view and our own becomes very evident here. Imagine all the atoms whereof Cæsar was made up at a given moment, say as he stood at the Rubicon, to be by mechanical power brought together, each in its own place, and possessed of its own velocity in its proper direction. In our view Cæsar would then be restored mentally as well as bodily. This artificial Cæsar would at the first instant have the same sensations, ambitions, imaginings, as his prototype on the Rubicon, and the same memories, the same inherited and acquired faculties, etc. Suppose several artificial figures of the same model to be simultaneously formed out of a like number of other carbon, hydrogen, etc., atoms. What would at the first moment be the difference between the new Cæsar and his duplicate, beyond the differences in the places where they were formed? But the mind imagined by Leibnitz, after fashioning the new Cæsar and his many Sosiæ, could never understand how the atoms he himself had disposed in order, and set into action with proper velocity, could give mental activity.

Take Carl Vogt's bold expression, which in 1850 introduced a sort of mental tournament: "All those capacities which we call mental activities are only functions of the brain; or, to use a rather homely expression, thought is to the brain what the bile is to the liver, or the urine to the kidneys." The unscientific world were shocked at the simile, considering it to be an indignity to compare thought with the secretion of the kidneys. Physiology knows no such aesthetic, discriminations of rank. In the view of physiology the kidney secretion is a scientific object of just the same dignity as the investigation of the eye, or the heart, or any so-called "nobler" organ. Nor is Vogt's expression worthy of blame on the ground that it represents mental activity as being the result of material conditions in the brain. Its faultiness lies in this, that it leaves the impression on the mind that the soul's activity is in its own nature as intelligible from the