Here’s a difficult question: Does an artificial heart literally become a body part of the patient?
And here’s a line of thought suggestive of a negative answer.
Necessarily, all our body parts are material.
If one could have an artificial heart as a body part, one could have an immaterial artificial heart as a body part.
So, one cannot have an artificial heart as a body part.
Why accept 2? Because presumably what makes an artificial heart suitable for being a body part is that it does the job of a heart. But we could imagine an immaterial being which does the job of a heart. For instance, an angel could move blood around the body, and do so in response to electrical activity in the brain stem. Perhaps one could say that an angel couldn't be a body part, because it is already an intelligent being. But we could then imagine something that moves blood around like the angel but doesn’t have a mind.
I am not so confident of premise 1, however. One could, I suppose, turn the argument around: An artificial heart could be a body part, so possibly some of our body parts are immaterial. And if that’s right, then given a view on which body parts are informed by the form of the person, we would have the further interesting conclusion that a form can inform something that isn’t matter.
What do you say to the person who rejects (2) because he believes that what makes something a part of a human body is its being informed by the soul of that human body?
ReplyDeleteAfter all, what makes digested food part of our bodies (feel free to call it whatever you think it is by the time it becomes part of our bodies rather than "digested food") is not that it does the job of nourishing us, because if it were nourishing us, it would still be food and not part of us. So something else has to be grounding the fact that it becomes part of us. And since the digestion of food is the paradigm case of stuff becomes part of our bodies, we should apply what we learn here to more exotic cases of stuff becoming part of us, such as in cases of artificial or natural organ transplants.
Just as food ceases to be food in virtue of becoming part of us, likewise, artificial hearts cease to be artificial hearts when they become part of us. The artifact is destroyed and its matter is assimilated into the body, just as with food. There is a something called a "heart" both before and after the transplant, but only by analogy.
I am happy to endorse everything you say except the rejection of (2). :-)
ReplyDeleteI think something immaterial can be informed by a form. For instance, I think the accidents of an angel are informed--in exactly the same sense as our body parts are (since on my view, our body parts are just constituted by accidents of us)--by the form of the angel.
But even if what *makes* something a part of the human body, there is the question of *why* it came to be informed by the form of the body. My suggestion was that the artificial (material) heart came to be informed by the form of the body (assuming it has done so) because it does the job of a heart. Its doing the job of a heart isn't constitutive of its being a heart, but maybe there is a law of nature (perhaps grounded in the human form) that anything that does the job of a heart comes to be a heart. (In the post, I talked of doing the job of a heart as what makes the artificial heart "suitable" for being a body part.) At least that seems to me to be the most plausible non-adhoc story about how artificial hearts come to be hearts (assuming they do).
I think something immaterial can be informed by a form. For instance, I think the accidents of an angel are informed--in exactly the same sense as our body parts are (since on my view, our body parts are just constituted by accidents of us)--by the form of the angel.
ReplyDeleteI think something immaterial can be informed by accidental forms only. I don't know what it would mean for a wholly immaterial substance to be informed by a substantial form that is distinct from it, and in fact I've never seen anybody suggest any such thing anywhere except as an attempt to maintain the survivalist position in the face of the fact that the soul is not the human person. Naturally, I think this is ad hoc.
You seem to suggest here that the information goes the opposite way from the way that Aquinas and I would say it goes. I would say that accidental forms inform the substance form of the angel, which is just the angel himself. But you say that the substantial form informs the accidents of the angel. Why? It's the angel that is in potential to the reception of the accident, not the accident in potential to reception of the angel, so I'm not sure why you'd want to say that the substantial form of an angel informs his accidents.
But even if what *makes* something a part of the human body, there is the question of *why* it came to be informed by the form of the body.
I agree that that is a distinction question, but that's that question about efficient causality (basically, about what efficiently caused this bit of matter to be assimilated by the human person in such a way that it became part of that person), whereas the former question was one about what constituted a bit of matter's being a part of the human person, which is question about formal causality, which is why I put the answer the way I did.
My suggestion was that the artificial (material) heart came to be informed by the form of the body (assuming it has done so) because it does the job of a heart. Its doing the job of a heart isn't constitutive of its being a heart, but maybe there is a law of nature (perhaps grounded in the human form) that anything that does the job of a heart comes to be a heart. (In the post, I talked of doing the job of a heart as what makes the artificial heart "suitable" for being a body part.) At least that seems to me to be the most plausible non-adhoc story about how artificial hearts come to be hearts (assuming they do).
Okay, reading this now as an answer to the efficient causality question rather than the formal causality one, I disagree. I would tell the same story about how artificial hearts come to be informed by the substantial form of the transplantee as would tell about how food comes to be so informed. Namely, some story about causal and material integration with the rest of the body. Of course, the stories about what counts as a heart and what counts as my heart, and therefore counts as part of my body, might come apart.
When a form informs matter, the matter thus informed has no existence apart from the form. The form gives the matter what actuality it has. Likewise, an accident (perhaps barring miraculous cases) has no actuality absent the form: the form gives it the actuality it has. The accident is partly grounded in the form, just as the matter is.
ReplyDeleteOn my own ontology, there is literally no difference between the form's relationship to material parts and the form's relationship to accidents, because the material parts are nothing but special accidents (ones with location, say).
Note that something immaterial could come to be causally integrated with the rest of the body. It wouldn't, of course, be materially incorporated. But perhaps it is only the causal incorporation that is relevant.
When a form informs matter, the matter thus informed has no existence apart from the form. The form gives the matter what actuality it has. Likewise, an accident (perhaps barring miraculous cases) has no actuality absent the form: the form gives it the actuality it has. The accident is partly grounded in the form, just as the matter is.
ReplyDeleteThis dependence goes in both directions in the case of material forms (i.e., forms which cannot subsist apart from the material substances of which they are the forms). The form of Rover the dog can no more exist apart from Rover's prime matter than can Rover's prime matter exist apart from his substantial form. So it doesn't follow from the fact that X can't exist apart from Y that X is the actuality of Y. If it did, we could just as easily say that Rover's matter is the actuality of his substantial form, which is absurd. Likewise, accidents, although they cannot naturally exist apart from their subjects, are the actuality of those subjects and not vice-versa, because accidents are what cause the subject to come to be actually such-and-such (e.g. red, legged, furry, etc.), and not subjects which cause their accidents to come to be actually such-and-such. So, for example, Rover is in potential to running; running is not in potential to existing in Rover.
I think two-way dependence is metaphysically impossible.
ReplyDeleteI still don't understand the Aristotelian "x is the actuality of y" language, except when it means "x is the proper effect of y". :-(
I agree that Rover is in potentiality to running. Likewise, I am in a realized potentiality to being embodied, and if I were disembodied, I would be in an unrealized potentiality to being embodied.
"The form of Rover the dog can no more exist apart from Rover's prime matter": I am not sure this is true, even if one weakens the claim by removing "prime". It wouldn't surprise me if the form of a dog, or a tree, could exist immaterially. It would probably take a miracle, though. If it can't, on my view that would just be a case of Rover's materiality being a necessary accident of Rover rather than of Rover having an ontological dependence on his materiality.