Ed Halper writes the following in reply to my post, quoted with his permission:
As I understood your question at the lecture, the problem is how to reconcile paradigmatism with the Categories' claim that substances do not admit of more and less. Man should indeed be more of an animal than other species if it is the primary species. What I suggested at the talk is that the Categories is the beginning of the Organon and, therefore, interested in setting the conditions for scientific knowledge. The latter consists of grasping that attributes belong to all instances of the genus in respect of its essential character. Since the attributes must belong to all instances as essential attributes, it is important that no instance be more or less.As regards the Categories, I did have in mind 3b33ff. ("It appears that substance does not admit of more or less....One man is not more a man than another"), although I interpret that passage as including in its scope 'secondary substances' as well as primary, and thus as holding that one could not, for instance, point to an individual man and to an individual horse and be correct in saying, 'This animal is more of an animal than that animal'. I also had in the back of my mind the opening of the Categories, where 'animal' said of an ox and of a man is given as the paradigm of synonomy: "the definition of what they are is the same".
Let me say, first of all that if paradigmatism turns out to be incompatible with the Categories, as I think your web post suggests, it will hardly be the first such incompatibility between the Categories and the Metaphysics! Indeed, you can chalk up my paper as still another reason to endorse some version of developmentalism or as expounding still another challenge to unitarians. My main concern was to show that the Metaphysics expounds a key doctrine that is important as an organizing principle in his other works. You do not undermine my point by showing that principle to conflict with the Categories (if it does).
The other "problems" that you mention do not seem to be real objections either. Aristotle regards human beings as paradigms for animals. It is not surprising that we, the best instance of the genus, would find dissimilarities between ourselves and other instances of the genus, nor that we would ascribe the generic character to people as a kind of insult. I think we do appeal to humans when we make claims about animals. Just listen to people talk about how intelligent or sensitive their pets are. I heard someone give a paper in which he claimed that his dog felt empathy for the suffering of other animals. I could not see how he could know this or why it would be an advantage for dogs--who, in my experience, are happy to hunt and eat other animals. There are more legitimate appeals to humans as standards for animals, and we find some in Aristotle's biological works, I argued.
So I don't think you have really given any reasons to reject the thesis of the paper, but I do appreciate your questions, particularly the one about the Categories. What I'm hesitating about is that I explained the Categories as a tool for science, but I also explained paradigmatism as such a tool. The challenge is whether the two can work together. In fact, what we see most often in the special sciences is paradigmatism. Besides what I cite in the paper, look at De Anima II.3 or at the way that local motion and ultimately the circular motions of the spheres become the paradigm for Physics. On the other hand, Aristotle does seek to make claims about the whole of a genus that require ignoring paradigm species. More needs to be said about how these two modes of inquiry work together. But, again, I'm not seeing the basis of conflict here: on the contrary, the exposition of paradigmatism opens a rich vein for reflection. I'm grateful for your drawing this to my attention.
One detail about the Categories. I take it you have in mind 3b33 ff. But there he explains that whereas one white is more white than another, one substance is not more of a substance than another. He seems to be comparing individual substances and perhaps issuing a prescient warning that responding to those pervasive internet ads will not make you more of a man. A better passage is 2b22 ff. But that is also a bit ambiguous since his point seems to be that one species applies to an individual instance no more than another species of the same genus applies to its instance. All this is peculiar to substance, in contrast with other categories where it apparently need not hold. So thinking about I.8, we could say a contrariety in a genus is always necessary to divide it into species. Sometimes those species are themselves contraries and admit of more and less, as in species of quality, but sometimes, as in species of substance, they do not. That the Categories emphasizes differences in genera is all the more appropriate against the background of Met. I where all seem to be analogous.