As a universal history of philosophy, the history of philosophy must become one great unity.

Greatness of mind becomes an object of love only when the power at work in it itself has a noble character

The great philosophers and the great works are standards for the selection of what is essential. Everything that we do in studying the history of philosophy ultimately serves their better understanding.

Even scientific knowledge, if there is anything to it, is not a random observation of random objects; for the critical objectivity of significant knowledge is attained as a practice only philosophically in inner action.

Philosophy is tested and characterised by the way in which it appropriates its history.

Only then, approaching my fortieth birthday, I made philosophy my life's work.

When language is used without true significance, it loses its purpose as a means of communication and becomes an end in itself.