The polemic between Erasmus and Luther over the free will flared up Valla's speculations about the limitations of reason and omnipotence of thought
, the dissymmetry and interplay between knowing and willing and his doubts about philosophy's power to define the perimeter of their theological philosophical debate.
The male imagination, disavowing all involvement in the production of monstrous offspring, attributed dissimilarity to the vis imaginativa, thereby crediting the mother with something like omnipotence of thought
. Huet cites Pietro Pomponazzi, professor of natural philosophy at Padua (writing in the sixteenth century): "when a woman imagines something during the sexual act, she indeed imprints its image on the fetus" (17).