The chief cause of human errors is to be found in the prejudices picked up in childhood.

Bad books engender bad habits, but bad habits engender good books.

Common sense is the most widely shared commodity in the world, for every man is convinced that he is well supplied with it.

There is nothing so far removed from us as to be beyond our reach, or so hidden that we cannot discover it.

... moral certainty is certainty which is sufficient to regulate our behaviour, or which measures up to the certainty we have on matters relating to the conduct of life which we never normally doubt, though we know that it is possible, absolutely speaking, that they may be false.

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.

The principal effect of the passions is that they incite and persuade the mind to will the events for which they prepared the body.