Whether the heart is susceptible to illness.
One inquires further whether the heart is susceptible to illness.
1. It seems so. Because syncopis and cardiaca are afflictions of the heart. But these are illnesses, and therefore, etc.
2. Moreover, nothing passes from one end to another except through a medium. But illness is a path to death, and the heart is subject to death, and therefore to illness.
3. In addition, every member that is capable of being extended or contracted beyond its requisite state can become ill. But the heart can be extended and contracted; therefore, etc., because a person dies on account of too much joy or sadness. Therefore, the heart can become ill.
The Philosopher says the opposite.
One must reply that there are four times when each illness is subject to treatment, namely, at its beginning, its growth, its stasis, and its decline. The beginning is when, while the illness is imminent, the animal begins to cease its customary operations. Growth is when the signs of illness intensify. But stasis is when the signs of illness reach such a limit that it cannot intensify with nature remaining; the time of decline is when the person begins to convalesce.
Further one must understand that a member can suffer in two ways: either per se or through another. Per se, when there is some pustule or other illness on the member itself; through another, as when some illness exists in one member and another suffers along with it.
Therefore, one can reply to the question in this way, that if we are speaking about an illness or some suffering arising from the pain in another member, then in this sense the heart can suffer and become ill, because whenever another member suffers the heart suffers. If we are actually speaking about its own illness, then this sort of illness can exist in the heart in terms of the beginning and growth [of illness], but in terms of stasis this is impossible, because in all things that are properly ordered, when the first ceases then all subsequent things cease as well. But the heart is the first member, and this is why when the heart ceases its proper operations it is impossible for the other members to use their proper operations. Therefore, so long as the animal endures, the heart is always healthy.
1. On to the arguments. To the first, one must reply that syncopis and cardiaca are illnesses in other parts; nevertheless, they are called afflictions of the heart because the heart ceases from its operations during them.
2. To the second argument one must reply that death is not universally the end of illness. Now sometimes it arises from no previous illness, and if some illness does precede it is not principally an illness of the heart but of the other members.
3. To the third argument one must reply that the heart expands in joy. Therefore, it can expand so much that it cannot close itself, and then the animal dies suddenly and without any illness. But during sadness the natural heat, spirit, and vital power retreat to the interior of the heart, while abandoning the exterior parts. Therefore, in this instance the heart sometimes closes so much that it cannot open itself further, and then death occurs. But both these forms of death, whether they arise from joy or sadness, arise without illness and suddenly. This is why, etc.
Whether the blood is generated first in the heart or in the liver.
One inquires further whether the blood is generated first in the heart or in the liver.
It seems that it is in the liver. For blood is generated in that part in which the other humors are generated. But this occurs in the liver and not in the heart, and therefore, etc.
Moreover, if food enters the windpipe, very often suffocation occurs, as the Philosopher says. Therefore, it is necessary that food be thinned and purified before it approaches the heart, because food passes through more members than air that has been breathed in, since food crosses from the stomach to the liver before it approaches the heart, and therefore, etc.
The Philosopher says the opposite.
One must reply that blood can be generated in two ways: either from something moist, as when it is generated from phlegm, or not from something moist, as when it is generated from chyle. And this second generation too can arise from something in two ways: either virtually or materially. And both of these also happen in two ways: either with respect to the whole, or to the part. In the first way, blood can be generated in any member, as when it is generated from something moist. In the second way it can be generated both in the heart and in the liver. But with respect to the whole and materially, it is generated in the liver; but with respect to the part and formally or virtually, it is generated in the heart because the blood generated in the liver is thick and not completely digested, but the blood generated in the heart is thin and perfectly digested. Therefore, according to the physicians the first generation of the blood occurs in the liver, and according to the Philosopher the first generation occurs in the heart, because according to the Philosopher the heart is the principle and origin of the veins, whereas according to the physicians this is the liver. And this controversy between the Philosopher and the physicians can be solved by the distinction of "the prior" because "prior" is said in two ways: in terms of generation, and in terms of perfection, as a boy is prior to the man in terms of generation but is not prior in terms of perfection. Thus, in the premise, blood is prior in the liver in generation and in time but it is prior in the heart in terms of perfection.
In this way one can make clear the solutions to the arguments, for they proceed by their own paths.
-  See DA 184.108.40.206 (SZ 2: 1472). Cardiaca can indicate many heart-related problems ranging from mere heartburn to more serious disorders involving either the heart or stomach. "Syncope" is a term still used for fainting.
-  "Windpipe": arteria. In DA A. regularly uses the term "artery" for the windpipe.