We assume a common sense as the necessary condition of the universal communicability of our knowledge, which is presupposed in every logic and every principle of knowledge that is not one of skepticism.
When ignorant people see someone who is dead, they are disgusted and horrified, even thought they too will be dead some day. I thought to myself: I don't want to be like the ignorant people. After then, I couldn't feel the usual intoxication with life anymore.
It is commonly observed that a sudden wealth, like a prize drawn in a lottery or a large bequest to a poor family, does not permanently enrich. They have served no apprenticeship to wealth, and with the rapid wealth come rapid claims which they do not know how to deny, and the treasure is quickly dissipated.
No one has yet been found so firm of mind and purpose as resolutely to compel himself to sweep away all theories and common notions, and to apply the understanding, thus made fair and even, to a fresh examination of particulars. Thus it happens that human knowledge, as we have it, is a mere medley and ill-digested mass, made up of much credulity and much accident, and also of the childish notions which we at first imbibed.
Upon a given body to generate and superinduce a new nature or new natures is the work and aim of human power. To discover the Form of a given nature, or its true difference, or its causal nature, or fount of its emanation... this is the work and aim of human knowledge.
In the scientific world I find just that disinterested devotion to great ends that I hope will spread at last through the entire range of human activity.