Truth comes out of error more readily than out of confusion.

The human understanding is like a false mirror, which, receiving rays irregularly, distorts and discolors the nature of things by mingling its own nature with it.

All colours will agree in the dark.

When I paint I am ageless, I just have the pleasure or the difficulty of painting.

The divisions of science are not like different lines that meet in one angle, but rather like the branches of trees that join in one trunk.

Vices of the time; vices of the man.

Observation and experiment for gathering material, induction and deduction for elaborating it: these are are only good intellectual tools.