The sciences which take socio-historical reality as their subject matter are seeking, more intensively than ever before, their systematic relations to one another and to their foundation.

What man is, only his history tells.

Ancient metaphysics underwent many changes at the hands of medieval thinkers who brought it in line with the dominant religious and theological movements of their day.

The knife of historical relativism... which has cut to pieces all metaphysics and religion must also bring about healing.

Any theory intended to describe and analyze socio-historical reality cannot restrict itself to the human spirit and disregard the totality of human nature.

If we conceive all the changes in the physical world as reducible to the motion of atoms, motions generated by means of the fixed nuclear forces of those atoms, the whole of the world could thus be known by means of the natural sciences.

The individual always realizes only one of the possibilities in his development, which could always have taken a different turning whenever he had to make an important decision.