Perhaps we may make a distinction between perfection that is greater in degree and perfection that is greater in kind. If we only insist on the latter when spelling out the principle of proportionate causality, we wind up only having to posit transmaterial intervention on three occasions: the origin of life, the origin of consciousness, and the origin of reason.

After all, even worms have faculties like the common sense, imagination, memory, estimation, etc. It's just that higher mammals can use those faculties in more complicated ways. Which means that transmission of information from the environment to the gene pool (the normal explanation for biological complexity) is a perfectly adequate explanation in this instance. If we want to explain the origin of such faculties in the first place, however - say, in explaining how a species of sponge gave rise to the first worms - we'll be needing something higher. In the earlier case, the higher mammals were more perfect than the worms merely in degree - the mammals have the same faculties, just more refined. In the present case, we can see that the worm is more perfect than the sponge in degree, as the sponge lacks sensation, the common sense, memory, imagination, estimation, and other faculties associated with the sensitive soul entirely.

Greg wrote:

I don't think that will work. There are lots of powers that all animals have in common with humans, but not all of them.[1] Oysters lack locomotion[2], in Aristotle's view, and from our standpoint it should probably look like there is even greater variation in the possession of various senses among animals.[3] (I am not familiar with the details of Aristotle's biology at all, but I understand that he does count sponges among animals rather than vegetables, and holds that they at least have perception/sensation--or, at least, a quick search seemed to show this, but he certainly thinks it's true of oysters.)[4]

[1] Which powers are you discussing? Intellect and will? In that case, I'm happy to agree. Other sensitive/appetitive powers that we have and they lack, or that they have and we lack? I might be able to agree with that as well, depending on the specifics.

[2] Contra Oderberg, Aristotle, et al., I am of the opinion that locomotion isn't particularly significant - metaphysically speaking - as powers go. There are a number of reasons for this.

A. The big reason being that I only like postulating a new kind of soul/substantial form in cases where the whole obviously becomes greater than the sum of its parts, and as far as I can tell, the only attributes (where anything said of or present in a thing counts as an attribute) that meet that criterion are life, consciousness, and reason.

B. Another factor is that there are many motile species that, presumably lacking consciousness, should not be considered animals. Many bacteria and "protozoans" would be counted as animals if we assumed that "locomotion" is something of which animals alone are capable.

C. A related point is that many sessile taxa go through a locomotory larval stage. The oyster is a key example here: for the first few weeks of its life, it is capable of moving around, though it ultimately settles down. Similar things could be said of barnacles and sea squirts. If locomotion were a fundamental power the way immanent causation, consciousness, and intelligence are, we would be forced to conclude that the larva undergoes corruption as soon as it sets down roots - that substantial change can occur in the middle of the lifetime of a single organism. I find that consequence absurd.

As a result of such considerations, I think that locomotion shouldn't be viewed as being ontologically fundamental in the way that life and reason are. I would propose that it be considered a proper accident of some animals, rather than a specific difference marking off animals as a whole (as it is according to Oderberg), or as a specific difference that divides "perfect" animals from imperfect ones (as, to my understanding, it is according to Aristotle). Instead, I would point to sentience alone as the mark of the animal.

As for identifying which animals are sentient, I would propose that the key corporeal mark is the centralization of stimulus/response pathways to a dedicated organ or system - ie. the presence of something like a nervous system.

[3] A different kind of sense is still a sense, and thus not the sort of thing we need to worry about. Anything that can cause physiological consequences can eventually end up getting hooked up to a sense organ - and thereby ending up as the material/efficient cause of a proper sensible (with the physiological consequences in the sense organ and/or elsewhere in the nervous system being the material/efficient cause of a corresponding phantasm).

[4] I see no reason to think that sponges are conscious. Plants exhibit responses to stimuli similar to (albeit usually slower than) those that sponges do; and things like bacteria are often even more animal-like in their behavior than sponges. But since none of them have organs dedicated to the centralized coordination of responses to stimuli, I wouldn't be willing to consider any of them animals.

However, I think it is also not going to be correct to characterize the difference between the prefections of two animals which do have all of the same powers (say, a horse and a dog) as a difference in degree rather than kind, unless all animals with the same set of powers are specifically the same, which they are not.

While the perfections of a horse are indeed different in kind from those of a dog, they are not greater in kind, nor are the dog's perfections greater in kind than those of the horse.

Last edited by Dave (7/26/2018 10:05 am)