Il difetto di giudizio è propriamente quello che si chiama stupidità, difetto cui non c'è modo di arrecare rimedio. Una testa ottusa o limitata, alla… - Immanuel Kant

I express the principle of one's freedom as a human being in this formula: No one can compel me (in accordance with his beliefs about the welfare of others) to be happy after his fashion.

act as if the maxim of your action were to become by your will a general law of nature.

Without sensibility no object would be given to us, without understanding no object would be thought. Thoughts without content are empty, intuitions without concepts are blind. It is, therefore, just as necessary to make our concepts sensible, that is, to add the object to them in intuition, as to make our intuitions intelligible, that is, to bring them under concepts. These two powers or capacities cannot exchange their functions. The understanding can intuit nothing, the senses can think nothing. Only through their union can knowledge arise. But that is no reason for confounding the contribution of either with that of the other; rather is it a strong reason for carefully separating and distinguishing the one from the other. We therefore distinguish the science of the rules of sensibility in general, that is, aesthetic, from the science of the rules of the understanding in general, that is, logic.