Handbook of the History of Logic: - Fordham University Faculty

86 Ian Wilks
are these items corresponding to the subject and predicate terms? Speaking of
animal instead of animals is to use a mass noun where we would normally use a
count noun. We know what animals are, but what is animal?
Notice how easily a Platonist can give a response. Animal can be taken as the
form of animality which all animals share, and in which they all participate. Man
can be taken as the shared form of humanity (or manness) common to all men.
Animal and man, taken thus, are single, distinct things, and are appropriately
denoted by unpluralized nouns. The above propositions just describe in various
ways, some true, some false, the relationship between these single, distinct things.
So in this way the conventional language of the categorical syllogism fairly
invites some kind of theory of shared forms — forms which exist independently of
the things that nonetheless share in them. 7 And this is why Porphyry’s Isagoge,
intended as a propaedutic to the study of logic, begins with these questions about
genera and species: “(1) Whether genera or species exist in themselves or reside in
mere concepts alone; (2) whether, if they exist, they are corporeal or incorporeal;
and (3) whether they exist apart or in sense objects and in dependence on them”
[Porphyry, 1975, pp. 27 (12)–28 (14)]. Aristotle himself did not ultimately accept
the existence of shared forms, but bequeathed a language which made them a live
issue. 8 Abelard could not avoid having some position on this issue.
He in fact did not accept the existence of shared forms either. Some people,
he says, “maintain that the same thing is essentially in many, so that the same
thing that is in this is essentially in that, although is furnished
with different forms. For example animal is in Socrates and in Brunellus and in
others” [Abelard, 1933, p. 515 (17–21)]. 9 So animal is shared by all animals;
in other words, they are all essentially the same animal because the form that
confers animality upon them is the same form. Accordingly, “Socrates is in no
way essentially different from Brunellus” [Abelard, 1933, p. 515 (23–24)]. Abelard
has a number of objections against this view [Abelard, 1933, pp. 515 (32)–518 (8)];
these emphasize the counter-intuitiveness of what it implies about individuality
– such as its implication that Socrates and Brunellus the ass are essentially the
same animal, since they share the same form of animality. Shared forms make
individuality impossible. The fact that individuals do exist entails that shared
forms do not.
Abelard is perfectly willing to speak of forms/genera/species, but not as accompanied
by anything like a Platonic theory of participation. While he does
7 By contrast, a theory of unshared forms posits distinct forms for distinct things. On this
theory, the animality of one animal is distinct from the animality of another animal. See note
10 below.
8 The relationship between Aristotle’s syllogistic and Plato’s method of division (for which,
see [Kneale and Kneale, 1962, pp. 44, 67–68]) would explain how Aristotle came to bequeath
such a language.
9 Abelard is describing the position now referred to as “Material Essence Realism.” This
position is associated with William of Champeaux, and articulates in some detail a metaphysics
of shared forms. For Material Essence Realism, and Abelard’s critique of the position, see
[Tweedale, 1976, pp. 95–111], [Gracia, 1984, pp. 198–200], and [King, 2004, pp. 66–69]. For
Abelard’s complex relationship to Platonism generally, see [Marenbon, 1997b].