From the crooked timber of humanity, a straight board cannot be hewn. - Immanuel Kant

Enlightenment is man's exodus from his self-incurred tutelage. Tutelage is the inability to use one's understanding without the guidance of another person..'Dare to Know'(sapere aude) Have the courage to use your own understanding;this is the motto of the Enlightenment.

It is impossible to conceive anything at all in the world, or even out of it, which can be taken as good without qualification, except a good will.

In every department of physical science there is only so much science, properly so-called, as there is mathematics.