an intellectual concept abstracts from everything sensuous, it is not abstracted from sensuous things, and perhaps would be more correctly called abs… - Immanuel Kant

Human reason, in one sphere of its cognition, is called upon to consider questions, which it cannot decline, as they are presented by its own nature, but which it cannot answer, as they transcend every faculty of the mind.

...[T]here is no art in being intelligible if one renounces all thoroughness of insight; but also it produces a disgusting medley of compiled observations and half-reasoned principles. Shallow pates enjoy this because it can be used for everyday chat, but the sagacious find in it only confusion, and being unsatisfied and unable to help themselves, they turn away their eyes, while philosophers, who see quite well through this delusion, are little listened to when they call men off for a time from this pretended popularity in order that they might be rightfully popular after they have attained a definite insight.

...[P]hysics... [is] the philosophy of nature, so far as it is based on empirical laws.