—Look forth, or each man dive into himself;
What sees he but a creature too perturbed;
That is transported to excess; that yearns,
Regrets, or trembles, wrongly, or too much;
Hopes rashly, in disgust as rash recoils;
Battens on spleen, or moulders in despair?
Thus comprehension fails, and truth is missed;
Thus darkness[462] and delusion round our path
Spread, from disease, whose subtle injury lurks
Within the very faculty of sight.