History of Monsters. 391

These monsters can be attributed partly to the imagination and partly to the voracity of animals, for the love of geese toward humans is well known (as I discussed in my *Ornithology*). Furthermore, it is clear that hens are of such a nature that they will devour all sorts of foul things—even semen and menstrual blood—and they do not even shrink from eating live snakes. Moreover, hens sometimes succumb to snakes, as the most excellent Liceto testifies from the observation of a servant girl who, on more than one occasion, saw a hen being "embraced" by an asp. At dawn, this hen would leave the house and hurry to the roots of an aged oak tree, calling out to her snake husband with a croak; her eggs subsequently hatched not chicks, but small serpents. Likewise, in reviewing material causes, Liceto mentions both the proximate and the remote. He identifies the remote cause as that common material shared by all sublunary living things, while he calls the proximate material of monsters the "living sublunary body," since monsters occur not only in human nature but also among beasts and plants.

If we turn our discussion to the efficient cause, we can cite many authors who attribute it to a poor proportion of qualities. For instance, when Albertus lists the four causes of monsters, he mentions this perverse proportion of qualities. Indeed, he adds that in his own time an androgynous child was born, so skillfully formed with both sexes that it was impossible to discern which was dominant. He believes this originated because the hot qualities (which produce a male) and the cold qualities (which produce a female) were so closely joined that, when a strong formative power acted upon them, a hermaphrodite was easily produced. The Parisian Regents followed this line of reasoning in a specific question in their commentary on the second book of the *Physics*, stating that monsters occur because of an unequal proportion of qualities, arising from the agent, the patient, or both. This view was not rejected by the most eminent Cardinal Toledo or the Coimbra College in their commentaries on the same book. In fact, Cornelius Gemma further confirms this when he says that those who place the universal cause of monsters in a "disturbed proportion" are reasoning correctly; by "disturbed proportion," he undoubtedly means a bad proportion of the four qualities.

The efficient cause of monsters is also called the "natural Agent" or its "formative power." When this power is vigorous, it may divide things that should not be separated; hence, some infants are born with six fingers on their hands or toes on their feet. At other times, it is so weak that it fails to separate what should be distinct. This results in offspring born with all their fingers joined together. Indeed, last year in Bologna, we saw a poor wandering beggar who had the fingers of his right hand joined together by a continuous nail. Similarly, Ludovico Mercado wrote that the formative faculty and the natural power of the Agent sometimes cannot control the material of the fetus as they should; consequently, depending on whether the Agent's impediment is greater or lesser, various monsters result. Therefore, there is no doubt that monsters are generated due to the nature of the Agent. No one can deny that a weakness of natural heat in the Agent would prevent nature from delineating and forming the body as necessary. This is attested by Averroes in his commentaries on Aristotle. Moreover, Albertus Magnus called the efficient cause the "formative power," asserting that monsters stem from a weakness in this power; when it is feeble, it cannot form the entire mass of material, but only delineates a portion and leaves the rest.

Others have championed celestial influences as the efficient cause of monsters. This stands against the opinion of those who convince themselves that a body as noble as the Heavens does nothing in these lower realms except produce light, and through light, heat. Yet Aristotle asserted in his *Meteorology* that all these sublunary things are governed by the power of the Heavens, and elsewhere that "man is begotten by man and by the Sun." Thus, many effects are produced in lower things by the various movements of the heavens and the aspects of the stars. The Heavens act not only through light and motion but also through other occult powers, which are subsequently called "influences." This was the opinion of Saint Thomas, Albertus Magnus, the Conciliator, Paolo Veneto, and John