In vulgar modern terms Newton was profoundly neurotic of a not unfamiliar type, but... a most extreme example. His deepest instincts were occult, esoteric, semantic — with profound shrinking from the world, a paralyzing fear of exposing his thoughts, his beliefs, his discoveries, in all nakedness to the inspection and criticism of the world. ...Until the second phase of his life, he was a wrapt, consecrated solitary, pursuing his studies by intense introspection.