“You put too much stock in human intelligence, it doesn't annihilate human nature.”

A Fairy Tale of New York (London: Eyre Methuen, 1973) p. 224.

Source: The Counterlife (1986), Ch. 5

Source: It Had to Be You

The Poet at the Breakfast Table (1872)

The Transhumanism Handbook, 2019

As quoted in Fighting Fire with Fire: African Americans and Hereditarian Thinking, 1900-1942 by Gregory Michael Dorr (RTF document) http://www.wfu.edu/~caron/ssrs/Dorr.rtf. Dorr dates this quote to 1910.

Vol.4. Part 2.
The End of the Republic and it's correspondence with the death of Cato.
The History of Rome - Volume 4: Part 2
Context: The constitutional struggle was at an end; and that it was so, was proclaimed by Marcus Cato when he fell on his sword at Utica. For many years he had been the foremost man in the struggle of the legitimate republic against its oppressors; he had continued it, long after he had ceased to cherish any hope of victory. But now the struggle itself had become impossible; the republic which Marcus Brutus had founded was dead and never to be revived; what were the republicans now to do on the earth? The treasure was carried off, the sentinels were thereby relieved; who could blame them if they departed? There was more nobility, and above all more judgment, in the death of Cato than there had been in his life. Cato was anything but a great man; but with all that short-sightedness, that perversity, that dry prolixity, and those spurious phrases which have stamped him, for his own and for all time, as the ideal of unreflecting republicanism and the favourite of all who make it their hobby, he was yet the only man who honourably and courageously championed in the last struggle the great system doomed to destruction. Just because the shrewdest lie feels itself inwardly annihilated before the simple truth, and because all the dignity and glory of human nature ultimately depend not on shrewdness but on honesty, Cato has played a greater part in history than many men far superior to him in intellect. It only heightens the deep and tragic significance of his death that he was himself a fool; in truth it is just because Don Quixote is a fool that he is a tragic figure. It is an affecting fact, that on that world-stage, on which so many great and wise men had moved and acted, the fool was destined to give the epilogue. He too died not in vain. It was a fearfully striking protest of the republic against the monarchy, that the last republican went as the first monarch came—a protest which tore asunder like gossamer all that so-called constitutional character with which Caesar invested his monarchy, and exposed in all its hypocritical falsehood the shibboleth of the reconciliation of all parties, under the aegis of which despotism grew up. The unrelenting warfare which the ghost of the legitimate republic waged for centuries, from Cassius and Brutus down to Thrasea and Tacitus, nay, even far later, against the Caesarian monarchy—a warfare of plots and of literature— was the legacy which the dying Cato bequeathed to his enemies. This republican opposition derived from Cato its whole attitude— stately, transcendental in its rhetoric, pretentiously rigid, hopeless, and faithful to death; and accordingly it began even immediately after his death to revere as a saint the man who in his lifetime was not unfrequently its laughing-stock and its scandal. But the greatest of these marks of respect was the involuntary homage which Caesar rendered to him, when he made an exception to the contemptuous clemency with which he was wont to treat his opponents, Pompeians as well as republicans, in the case of Cato alone, and pursued him even beyond the grave with that energetic hatred which practical statesmen are wont to feel towards antagonists opposing them from a region of ideas which they regard as equally dangerous and impracticable.

Flowers for Algernon (1966)
Context: Don't misunderstand me," I said. "Intelligence is one of the greatest human gifts. But all too often a search for knowledge drives out the search for love. This is something else I've discovered for myself very recently. I present it to you as a hypothesis: Intelligence without the ability to give and receive affection leads to mental and moral breakdown, to neurosis, and possibly even psychosis. And I say that the mind absorbed in and involved in itself as a self-centered end, to the exclusion of human relationships, can only lead to violence and pain.