"The life of study is austere and imposes grave obligations. It pays, it pays richly; but it exacts an initial outlay that few are capable of. The athletes of the mind, like those of the playing field, must be prepared for privations, long training, a sometimes superhuman tenacity. We must give ourselves from the heart, if truth is to give itself to us. Truth serves only its slaves."
- A. G. Sertillanges from The Intellectual Life: Its Spirit, Conditions, Methods