I believe there exists, & I feel within me, an instinct for the truth, or knowledge or discovery, of something of the same nature as the instinct of virtue, & that our having such an instinct is reason enough for scientific researches without any practical results ever ensuing from them.

Certain it is that a conviction, akin to religious feeling, of the rationality or intelligibility of the world lies behind all scientific work of a higher order.

Every serious scientific worker is painfully conscious ... of being relegated to an ever-narrowing sphere of knowledge.

I never made one of my discoveries through the process of rational thinking.

There is no logical way to the discovery of these elemental laws. There is only the way of intuition, which is helped by a feeling for the order lying behind the appearance.

A scientific man ought to have no wishes, no affections, - a mere heart of stone.