Note 528 — Chapter XXVIII

Principles of Biology, part iii. chaps. xi, xii.—Goltz and Loeb have found that dogs become mild in character when their occipital, and fierce when their frontal, brain-lobes are cut off. "A dog which originally was cross in an extreme degree, never suffering himself to be touched, and even refusing, after two days' fasting, to take a piece of bread from my hand, became, after a bilateral operation on the occipital lobes, perfectly trustful and harmless. He underwent five operations on these parts.... Each one of them made him more good-natured; so that at last (just as Goltz observed of his dogs) he would let other dogs take away the very bones which he was gnawing" (Loeb, Pflüger's Archiv, xxxix. 300). A course of kind treatment and training might have had a similar effect. But how absurd to call two such different causes by the same name, and to say both times that the beast's 'experience of outer relations' is what educates him to good-nature. This, however, is virtually what all writers do who ignore the distinction between the 'front-door' and the back-door' manners of producing mental change.

One of the most striking of these back-door affections is susceptibility to the charm of drunkenness. This (taking drunkenness in the broadest sense, as teetotalers use the word) is one of the deepest functions of human nature. Half of both the poetry and the tragedy of human life would vanish if alcohol were taken away. As it is, the thirst for it is such that in the United States the cash-value of its sales amounts to that of the sales of meat and of bread put together. And yet what ancestral 'outer relation' is responsible for this peculiar reaction of ours? The only 'outer relation' could be the alcohol itself, which, comparatively speaking, came into the environment but yesterday, and which, so far from creating, is tending to eradicate, the love of itself from our mental structure, by letting only those families of men survive in whom it is not strong. The love of drunkenness is a purely accidental susceptibility of a brain, evolved for entirely different uses, and its causes are to be sought in the molecular realm, rather than in any possible order of 'outer relations.'