“After all, the cultivated person's first duty is to be always prepared to rewrite the encyclopaedia.”

Aleph (2011)

As quoted in A Crowd of One: The Future of Individual Identity (2007) by John Clippinger, p. 130
Compare: "The distinguishing property of man is to search for and to follow after truth." – De Officiis, Book I, 13
Disputed

The Analects, The Great Learning
Context: The ancients who wished to illustrate illustrious virtue throughout the Kingdom, first ordered well their own states. Wishing to order well their states, they first regulated their families. Wishing to regulate their families, they first cultivated their persons. Wishing to cultivate their persons, they first rectified their hearts. Wishing to rectify their hearts, they first sought to be sincere in their thoughts. Wishing to be sincere in their thoughts, they first extended to the utmost their knowledge. Such extension of knowledge lay in the investigation of things.
Things being investigated, knowledge became complete. Their knowledge being complete, their thoughts were sincere. Their thoughts being sincere, their hearts were then rectified. Their hearts being rectified, their persons were cultivated. Their persons being cultivated, their families were regulated. Their families being regulated, their states were rightly governed. Their states being rightly governed, the whole kingdom was made tranquil and happy.
From the Son of Heaven down to the mass of the people, all must consider the cultivation of the person the root of everything besides.

Source: The Doctrine of the Mean

Source: All the Pretty Horses

As quoted by Theodore F. Wolff in The Christian Science Monitor (25 March 1985)
Posthumous quotes

The Analects, The Great Learning
Context: The ancients who wished to illustrate illustrious virtue throughout the Kingdom, first ordered well their own states. Wishing to order well their states, they first regulated their families. Wishing to regulate their families, they first cultivated their persons. Wishing to cultivate their persons, they first rectified their hearts. Wishing to rectify their hearts, they first sought to be sincere in their thoughts. Wishing to be sincere in their thoughts, they first extended to the utmost their knowledge. Such extension of knowledge lay in the investigation of things.
Things being investigated, knowledge became complete. Their knowledge being complete, their thoughts were sincere. Their thoughts being sincere, their hearts were then rectified. Their hearts being rectified, their persons were cultivated. Their persons being cultivated, their families were regulated. Their families being regulated, their states were rightly governed. Their states being rightly governed, the whole kingdom was made tranquil and happy.
From the Son of Heaven down to the mass of the people, all must consider the cultivation of the person the root of everything besides.

Variant: Long before morning I knew that what I was seeking to discover was a thing I'd always known. That all courage was a form of constancy. That it is always himself that the coward abandoned first. After this all other betrayals come easily.
Source: All the Pretty Horses

Source: The Wedding