Suffering is a spiritual thing. It is the most immediate revelation of consciousness, and it may be that our body was given us simply in order that suffering might be enabled to manifest itself. A man who had never known suffering, either in greater or less degree, would scarcely possess consciousness of himself. The child first cries at birth when the air, entering into his lungs and limiting him, seems to say to him: You have to breathe me in order to live!

The Tragic Sense of Life (1913) - IX : Faith, Hope, and Charity