Whether a softer heart is better.
One inquires further whether a softer heart is better.
It seems not. For every dry thing, the hotter it is, the harder it is. But the heart is dry, as has been said. Therefore, the hotter the heart, the harder. But the harder it is, the better it is, and therefore, etc.
In addition, that member is better disposed which can better resist harmful things. But the harder the heart is, the better it can resist harmful things. Therefore, etc.
The Philosopher says the opposite.
One must say that softness can arise from two causes: either from a defect in power and in natural heat that is unable to consume the superfluities and to harden a member, and this type of softness is in women when compared to men. Or, softness can arise from an abundance of blood, and this type of softness can be in one animal compared to another, and this type of softness is a sign of a good disposition, because in the second book of On the Soul the Philosopher says of this type that "those soft in flesh are sharp in mind." But the first type of softness is a sign of mobility, inconstancy and defect, and this is why women are more inconstant and changeable than men. Therefore, the Philosopher understands in the second way that a softer heart is better, and not in the first way. And, just as a statement has been made about softness, so too by way of opposition a distinction must be made about hardness.
And in this way one can respond to the Philosopher.
Whether the heart is hotter than the spirit.
One inquires further whether the heart is hotter than the spirit.
It seems not. In the genus of hot things those that are more rarefied [subtiliora] are hotter. But spirit is more rarefied than the heart. And therefore, etc.
In addition, the heart is situated opposite to the brain, so that the heart's heat will be tempered by the brain's coldness, and vice versa. But this is not the case for the spirits, since they are not situated opposite the brain, and therefore, etc.
To the contrary. That which is the principle of heat in something is hotter than is a derived heat [principiato calore] in something. But the heart is the principle of heat and of the spirits, and therefore, etc.
One must reply that one thing can be hotter than another in two ways: either formally or accidentally. Formally, the more rarefied are hotter than the dense, as air is hotter than water and fire hotter than earth. But accidentally, heated solids are hotter than rarefied things, seeing that the heat is incorporated into them more and is preserved longer. This is why heated iron heats more than the hottest water, owing to the subject's solidity. And this is why, formally speaking, the spirits are hotter than the heart, but speaking accidentally the heart is hotter than the spirits because it is more solid than they are, and this is why the heat is incorporated into it more and is retained longer.
By this, a solution to the arguments is apparent.
Whether a heart so flows to the other parts that it receives nothing from them.
One inquires further whether a heart flows to the other parts in such a way that it receives nothing from them.
It seems not. Because everything acting physically undergoes something when acting and is moved when moving. But the heart is a thing that moves physically and acts. Therefore, it undergoes something and is moved. But every thing that is moved and undergoes something receives something from something else. Therefore, etc.
Moreover, the heart is situated opposite the brain, so that it receives tempering from the brain's coldness. Therefore, it does not flow to the other parts in such a way that it receives something from others.
The Philosopher says the opposite.
To this, one must reply that some members are only receiving members, like flesh and bone, and others are receiving members and also flow out to others, like nerve and vein, since what they receive from others they infuse into others, and then there is some member that so infuses that it does not receive. This is apparent from the Philosopher's argument in the eighth book of the Physics, where he says that if two can be found joined and still another can be found that exists per se, and yet another remaining one can be found that exists per se, as if something is both moving and moved, and something else is so moved that it is not moving, then it will also be possible to find something that is so moving that it is not moved. So in his premise. But this rule should be understood with respect to things that are united accidentally.
Nevertheless, one must understand that reception is of two types: one is virtual and the other is material. And the material can be of many types, just as one of the members receives from another so that what has been lost is restored or so that its disposition will be rendered temperate. And the heart receives from the other members in these ways. For it receives nutriment from the stomach and from the liver and veins, for it is subject to loss just as are the other members. Moreover, it receives cooling through the lungs' drawing power, because the lungs serve as a fan for the heart, and likewise it receives cooling through the coldness that flows in from the brain. But virtual reception does not suit the heart in comparison to the other members because the heart is the first seat and first dwelling or domicile for the soul, infusing power to all the other members, and it does not receive power from them but only accidental or material dispositions.
In this way a solution to the arguments is apparent. For they prove that the heart receives something from other parts, but they do not show that power flows to it from other parts.
-  "Flows to": throughout this section, A. uses the verb influo without restraint. At any given time it can mean "flow to," "influence," or "infuse." Cf.