There will always be some people who think for themselves, even among the self-appointed guardians of the great mass who, after having thrown off the yoke of immaturity themselves, will spread about them the spirit of a reasonable estimate of their own value and of the need for every man to think for himself.
Immanuel KantI assert that, in any particular natural science, one encounters genuine scientific substance only to the extent that mathematics is present.
Immanuel KantBut although all our knowledge begins with experience, it does not follow that it arises from experience.
Immanuel Kant