Reason is nothing without imagination.

I was convinced that our beliefs are based much more on custom and example than on any certain knowledge.

It must not be thought that it is ever possible to reach the interior earth by any perseverance in mining: both because the exterior earth is too thick, in comparison with human strength; and especially because of the intermediate waters, which would gush forth with greater impetus, the deeper the place in which their veins were first opened; and which would drown all miners.

We never understand a thing so well,and make it our own, as when we have discovered it for ourselves.

There is nothing so strange and so unbelievable that it has not been said by one philosopher or another.

Intuition is the undoubting conception of a pure and attentive mind, which arises from the light of reason alone, and is more certain than deduction.

Except our own thoughts, there is nothing absolutely in our power.