Petroleum is a more likely cause of international conflict than wheat.

It is only from the light which streams constantly from heaven that a tree can derive the energy to strike its roots deep into the soil. The tree is in fact rooted in the sky.

science has now been for a long time - and to an ever-increasing extent - a collective enterprise. Actually, new results are always, in fact, the work of specific individuals; but, save perhaps for rare exceptions, the value of any result depends on such a complex set of interrelations with past discoveries and possible future researches that even the mind of the inventor cannot embrace the whole.

One does not play Bach without having done scales. But neither does one play a scale merely for the sake of the scale.

I am not a Catholic; but I consider the Christian idea, which has its roots in Greek thought and in the course of the centuries has nourished all of our European civilization, as something that one cannot renounce without becoming degraded.

There are only two sorts of greatness: true greatness, which is of a spiritual order, and the old, old lie of world conquest. Conquest is an ersatz greatness.

Uprooting is by far the most dangerous of the ills of human society, for it perpetuates itself.