In every great time there is some one idea at work which is more powerful than any other, and which shapes the events of the time and determines their ultimate issues.
The human understanding, when any preposition has been once laid down... forces everything else to add fresh support and confirmation; and although more cogent and abundant instances may exist to the contrary, yet it either does not observe them or it despises them, or it gets rid of and rejects them by some distinction, with violent and injurious prejudice, rather than sacrifice the authority of its first conclusions.
But by far the greatest obstacle to the progress of science and to the undertaking of new tasks and provinces therein is found in this-that men despair and think things impossible.
My praise shall be dedicated to the mind itself. The mind is the man, and the knowledge is the mind. A man is but what he knoweth. The mind is but an accident to knowledge, for knowledge is the double of that which is.
The human understanding when it has once adopted an opinion (either as being the received opinion or as being agreeable to itself) draws all things else to support and agree with it.
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.