Again I warn you, beware of philosophers and great reasoners. They will always be a snare to you, and will do you more harm than you will know how to do them good. They linger and pine away in discussing exterior trifles, and never reach the knowledge of the truth. Their curiosity is an insatiable spiritual avarice. They are like those conquerors who ravage the world without possessing it. Solomon, after a deep experience of it, testifies to the vanity of their researches.

—François Fénelon, Spiritual Progress

It is now four months since I have had any leisure for study; but I am very happy to forego study, and not to cling to anything, when providence would take it away. It may be that during the coming winter I shall have leisure for my library, but I shall enter it then, keeping one foot on the threshold, ready to leave it at the slightest intimation. The mind must keep fasts as well as the body. I have no desire to write, or speak, or to be spoken about, or to reason, or to persuade any. I live every day aridly enough, and with certain exterior inconveniences which beset me; but I amuse myself whenever I have an opportunity, if I need recreation.

—François Fénelon, Spiritual Progress

Augustine does not condemn all observation of the natural, but he does condemn seeking knowledge of the created world for its own sake and for the achievement of having understood it, rather than for what it can reveal about its creator.

St. Augustine’s Confessions – Summary and Analysis Book 10: Chapters 26-34

Students and learned men of every kind and every age go as a rule in search of information, not insight. They make it a point of honour to have information about everything: it does not occur to them that information is merely a means towards insight and possesses little or no value in itself. When I see how much these well-informed people know, I sometimes say to myself: Oh, how little such a one must have had to think about, since he has had so much time for reading!

—Arthur Schopenhauer, Essays and Aphorisms (Classics)

To estimate a genius you should not take the mistakes in his productions, or his weaker works, but only those works in which he excels. For even in the realm of the intellect, weakness and absurdity cleave so firmly to human nature that even the most brilliant mind is not always entirely free of them: whence the mighty errors which can be pointed to even in the works of the greatest men,

—Arthur Schopenhauer, Essays and Aphorisms (Classics)