Whether bloodless animals are naturally cold.
Whether bloodless animals living in the water are edible, but not those that live in air.
We have already said above," etc. With respect to this fourth book one may first ask about bloodless animals. And first, whether bloodless animals are naturally hot or cold.
1. And it seems that they are hot. This is because the container draws the content to its own complexion. But the sea is salty and, consequently, hot. Therefore, marine animals and those lacking blood are hot.
2. Moreover, flyers are hot and dry. But some bloodless animals are flyers, like bees and wasps. Therefore, such creatures are hot. Therefore, conversely, bloodless creatures will <not> be naturally cold. The proof of the consequence or of the converse follows this rule of the Topics: "When you have two contraries, if some property is in the one, the contrary property will be in the other."
3. Moreover, an animal has a certain complexion and it tolerates badly weather similar to its complexion, and tolerates well weather unlike its complexion. This is why a choleric creature tolerates summer badly but winter well, and a phlegmatic one tolerates winter badly but summer well, and similarly for the others. But bloodless animals, like flies and bees and crabs, are generated in summer and tolerate it well, but they are corrupted in winter. Therefore, they are naturally cold.
Related to this, one asks why bloodless animals living in water are edible, like oysters and crabs and marine shellfish, but those that live in the air are not, like bees and flies, because bees and wasps are poisonous and hot, just as scorpions are poisonous and cold.
To the first, one must reply that complexion can be considered three ways: either according to genus (and thus every living thing is said to be hot and moist, because life endures on account of these); or, in a second way, according to species, and thus a human is said to be hot and moist, but the ass is hot and dry, as is the lion. There is a third way, according to the individual, and this can be considered in two ways: either comparatively or absolutely: comparatively, just as one woman is said to be choleric in comparison with another, even though all women are naturally phlegmatic; if absolutely, then this person is said to be choleric, and that one sanguine.
When, then, one asks whether bloodless creatures are cold or hot, one must respond that according to the genus, i.e., in general, they are hot and moist, insofar as they are alive. With respect to the species, they are all cold, inasmuch as they are bloodless, because when the heat in the heart of an animal is adequate, it converts food into blood, but when the heat is weak, food cannot be adequately digested or converted into blood, but instead is converted into slime [ virus] and wateriness. If, however, we speak according to the individual and comparatively, then some are warm in comparison to others, because flyers are warm in comparison to those that exist in water and when compared to themselves, when they are dead. Thus one must reply to the question briefly by saying that they are naturally cold.
1. On to the arguments. To the first, one should say that complexion is twofold: natural and accidental. Now the sea, or the complexion of the sea, since it is water, is naturally cold and moist, but accidentally it is warm and dry on account of the saltiness and earthiness with which it is mixed, and the container draws the content to its natural, and not accidental, complexion. And besides this, although such animals live in a salty, bitter, or warm sea, they are nevertheless nourished by that which is sweet and cold and moist in it.
2. To the second argument one must reply that flyers lacking blood are naturally cold; nevertheless, in comparison with others, they can be called hot (or they are hot) with an elemental but not with a life-giving heat.
To another matter, which is asked in relation to this, one must say that in the human the complexion abounds with blood, and bloodless animals thus are far removed from the human complexion, but in aquatic animals, that which is gross and poisonous is converted into shells and hard skins, and that which remains of their substance is cleansed through the salt of the sea. Thus cleansing with seawater is effective against itching and mange. This is why the skin of a crab is red, because whatever in it stems from slime (or poison) and heat goes into the shell, and reddens it. This is because it is in the nature of heat to tinge by reddening, and when cooked they are redder, because the black earthiness and muddiness darkening their skin is washed away by cooking. But in flying animals this cause is absent (that is, the washing-away of poison through seawater or through something else, like a shell). For this reason all bloodless flyers are poisonous to humans and are not a food to any extent [secundum magis et minus].
And if it is objected that such animals are nourished by sweet and suitable food, as bees are (and because flies are nourished by flesh, milk, and the like), and that as a result it would seem that they are not poisonous to humans, it must be said that the sweet nutriment that is received from flowers is converted into the substance of such animals and it is infected and altered in them, and for that reason, although they are nourished by agreeable foods, nevertheless they themselves are not suitable food.
Moreover, although that which is made by them, like honey, is nourishment for a human, it still does not follow that these in themselves and in their substance are edible, because a honeycomb does not come from the substance of such animals, but is rather fashioned with skill, using a kind of prudence and a kind of natural instinct or skill they possess, and it is not generated from their substance but comes from somewhere else. One might imagine that it is gathered by them from flowers and other things and this is why it does not receive infection from their complexion, and although the honey may receive a bit of sharpness from them, it is nevertheless slight.
-  This is a loose translation of the exceedingly terse and cryptic Si oppositum in opposito, et propositum in proposito, which seems to reproduce Boethius's rendering of Ar., Topica 7.3 (153a33ff.)Nam si opposita oppositae, et eam (quae dicta est)propositi necesse est esse. (PL 64: 990D.) Cf. A., Topica 7.2.1. The phrase is invoked again at QDA 13.1, to show that if sickness is present in one who is ill, so health will be present in one who is healthy.
-  Secundum genus, idest [sic] in genere.