Philosophic depth > breadth

True knowledge, (scientia, science in its fundamental sense) lies in depth rather than in superficial extent. Science is knowledge through causes, and causes go down deep like roots. We must always sacrifice extent to penetration, for the reason that extent in itself is nothing, and that penetration, introducing us to the central point of observed facts, gives us the substance of what interminable pursuit ought to discover.

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When the whole field of study has been surveyed and its connections and unity estimated in the light of fundamental principles, it is urgently necessary, if one does not want merely to mark time, to turn to some task which is precise, defined in its limits, proportioned to one's strength: and then to throw oneself into it with all one's heart.

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Everyone in life has his work; he must apply himself to it courageously and leave to others what Providence has reserved for others. We must keep from specialization as long as our aim is to become cultivated men, and, as far as concerns those to whom these pages are addressed, superior men; but we must specialize anew when we aim at being men with a function, and producing something useful. In other words, we must understand everything but in order to succeed in doing some one thing.

Sertillanges 118,119