Sanity Check

Conditions of degeneration in the organic world are approximately known. These conditions are often of two distinct kinds, deprivation of food, light, etc. so leading to imperfect nutrition and enervation; the other, a life of repose, with abundant supply of food and decreased exposure to the dangers of the environment. It is noteworthy that while the former only depresses, or at most distinguishes the specific type, the latter, through the disuse of the nervous and other structures etc. which such a simplification of life involves, brings about that far more insidious and through degeneration seen in the life history of myriads of parasites.

--Patrick Geddes