Our reasonings grasp at straws for premises and float on gossamers for deductions.

An unflinching determination to take the whole evidence into account is the only method of preservation against the fluctuating extremes of fashionable opinion.

The only use of knowledge of the past is to equip us for the present.

...the self-satisfied dogmatism with which mankind at each period of its history cherishes the delusion of the finality of existing modes of knowledge.

In a living civilization there is always an element of unrest, for sensitiveness to ideas means curiosity, adventure, change. Civilized order survives on its merits and is transformed by its power of recognizing its imperfections.

Seek simplicity, and distrust it.

A man of science doesn't discover in order to know, he wants to know in order to discover.