Reason is impaired by passions

This does the poor philosopher reason when he undertakes to reason at moments when a tumultuous passion leads the divine faculties of his soul astray. To reason rightly one must be neither in love nor in anger; for those two passions reduce as to the level of animals; and unfortunately we are never so much inclined to reason as when we are agitated by one or the other of them.

Giacomo Casanova - History of my life (2, 1)

The human nature always prevails

LEONATO:

For there was never yet philosopher
That could endure the toothache patiently,
However they have writ the style of gods
And made a push at chance and sufferance.

William Shakespeare - Much ado about nothing (5.1)