One should not be deceived: great spirits are skeptics ... Strength, FREEDOM which is born of the strength and overstrength of the spirit, proves itself by skepticism. Men of conviction are not worthy of the least consideration in fundamental questions of value and disvalue. Convictions are prisons.
One must never have spared oneself, one must have acquired hardness as a habit to be cheerful and in good spirits in the midst of nothing but hard truths.
A wise writer will feel that the ends of study and composition are best answered by announcing undiscovered regions of thought, and so communicating, through hope, new activity to the torpid spirit.