This integrative action in virtue of which the nervous system unifies from separate organs an animal possessing solidarity, an individual, is the problem before us.

As followers of natural science we know nothing of any relation between thoughts and the brain, except as a gross correlation in time and space.

If we denote excitation as an end-effect by the sign plus (+), and inhibition as end-effect by the sign minus (-), such a reflex as the scratch-reflex can be termed a reflex of double-sign, for it develops excitatory end-effect and then inhibitory end-effect even during the duration of the exciting stimulus.

Further study of central nervous action, however, finds central inhibition too extensive and ubiquitous to make it likely that it is confined solely to the taxis of antagonistic muscles.

This integrative action in virtue of which the nervous system unifies from separate organs an animal possessing solidarity, an individual, is the problem before us.

That our being should consist of two fundamental elements [physical and psychical] offers I suppose no greater inherent improbability than that it should rest on one only.

Natural knowledge has not forgone emotion. It has simply taken for itself new ground of emotion, under impulsion from and in sacrifice to that one of its 'values', Truth.