[3] Though it appears doubtful whether he practiced as a physician at Huesca, Huarte distinguished himself by his professional skill and heroic zeal during the plague which devastated Baeza in 1566.

[3] Huarte published the first edition of his Examen de ingenios para las ciencias (The Examination of Men's Wits) in 1575, which won him a European reputation, and was translated by Gotthold Ephraim Lessing.

[4] Though now superseded, Huarte's treatise is historically interesting as the first attempt to show the connection between psychology and physiology, and its acute ingenuity is as remarkable as the boldness of its views.

While Huarte wanted children to begin acquiring knowledge related to their talents at a young age, he was aware that the tasks would have to be developmentally appropriate.

Children, on the other hand, were believed to have the opposite problem: they had moist brains useful for memory tasks, but were low in understanding because they were lacking dryness.

Huarte also stated that for everyone, memory is better in the morning and worsens throughout the day because brains accumulate moisture while sleeping and dry out over the waking hours.

His theory on this combined Greek philosophy with significance placed on the natural determinants of behavior and Christian theology with attention drawn to miraculous enlightenment.

In conjunction with this, Huarte taught that intelligence is stored in the testicles, thus justifying his theory that women are, by nature more stupid than men.

[11] Historians can interpret these paternalistic biases coinciding with his desire to understand individual differences as insight into how psychologists shaped and supported social norms during and after their time, and use this knowledge to question other gender-differentiated results.

His influence can be seen (though not always cited) in the work of Miguel de Cervantes (whose Don Quixote was inspired by him), Francis Bacon, Pierre Charron, Immanuel Kant, Noam Chomsky, Johann Wolfgang von Goethe, David Hume, Montesquieu, Friedrich Nietzsche, Francisco de Quevedo, Jean-Jacques Rousseau, Arthur Schopenhauer, Jakob Thomasius, and Gotthold Ephraim Lessing.