It is often found to affect the hereditarily rheumatic or gouty.
Helmholtz also wrote on philosophical and aesthetic problems. His position was that of an empiricist, denying the doctrine of innate ideas and holding that all knowledge is founded on experience, hereditarily transmitted or acquired.
He throws out the brilliant suggestion that the experience of the race is in a sense inherited by the individual; which is true in the sense that animal organisms become hereditarily better adapted to perform mental operations, though no proof that any elements of knowledge become a priori.
The view that instinct is the hereditarily fixed result of habit derived from experience long dominated all inquiry into the subject, but we may now expect to see a renewed and careful study of animal instincts carried out with the view of testing the applicability to each instance of the pure Darwinian theory without the aid of Lamarckism.
The rough experience of this voyage did more than endow him with renewed health; it changed him from a dreamy, sensitive boy, hereditarily disinclined to any sort of active career, into a selfreliant, energetic man, with broad interests and keen sympathies.