Those however who aspire not to guess and divine, but to discover and know; who propose not to devise mimic and fabulous worlds of their own, but to examine and dissect the nature of this very world itself; must go to facts themselves for everything.

Nor can the place of this labour and search and worldwide perambulation be supplied by any genius or meditation or argumentation; no, not if all men's wits could meet in one.

This therefore we must have, or the business must be for ever abandoned.
But up to this day such has been the condition of men in this matter, that it is no wonder if nature will not give herself into their hands.
For first, the information of the sense itself, sometimes failing, sometimes false; observation, careless, irregular, and led by chance; tradition, vain and fed on rumour; practice, slavishly bent upon its work; experiment, blind, stupid, vague, and prematurely broken off; lastly, natural history, trivial and poor;--all these have contributed to supply the understanding with very bad materials for philosophy and the sciences.
Then an attempt is made to mend the matter by a preposterous subtlety and winnowing of argument.

But this comes too late, the case being already past remedy; and is far from setting the business right or sifting away the errors.

The only hope therefore of any greater increase or progress lies in a reconstruction of the sciences.
Of this reconstruction the foundation must be laid in natural history, and that of a new kind and gathered on a new principle.