“Philosophy when superficially studied, excites doubt, when thoroughly explored, it dispels it.”

“In practice people who study philosophy too long become very odd birds, not to say thoroughly vicious; while even those who are the best of them are reduced by...[philosophy] to complete uselessness as members of society.”

“Let no one delay the study of philosophy while young nor weary of it when old.”

“Keep in mind that when sin is viewed superficially, it is dealt with superficially.”

“Faith and doubt cannot reside in the same mind at the same time, for one would dispel the other.”

“‎And when this intoxication has worn away... when every desire is fulfilled and every language learned- when there are no more distant cities to explore; no classics to be studied; not another coin to be stuffed in to one's coffers- what then? One can have all the comforts of the world, but what use are they if there is no comfort in them?”