Experience is the only teacher we have. We may talk and reason all our lives, but we shall not understand a word of truth until we experience it ourselves.

A teacher can never truly teach unless he is still learning himself. The teacher who has come to the end of his subject, who has no living traffic with his knowledge but merely repeats his lesson to his students, can only load their minds, he cannot quicken them.

My works are the issue of simple and plain experience which is the true mistress.

To me it seems that those sciences are vain and full of error which are not born of experience, mother of all certainty, first-hand experience which in its origins, or means, or end has passed through one of the five senses.

I know that many will call this useless work. Though I may not, like them, be able to quote other authors, I shall rely on that which is much greater and more worthy-on experience, the mistress of their Masters.

Experience is never at fault; it is only your judgment that is in error in promising itself such results from experience as are not caused by our experiments. For having given a beginning, what follows from it must necessarily be a natural development of such a beginning, unless it has been subject to a contrary influence, while, if it is affected by any contrary influence, the result which ought to follow from the aforesaid beginning will be found to partake of this contrary influence in a greater or less degree in proportion as the said influence is more or less powerful than the aforesaid beginning.