39 On One
On One be predicated both potentially and actually. But note: things do not sleep or have knowledge except actually.
We will talk about the other divisions in being elsewhere..In the interests of brevity these remarks will suffice for the present.
39: On One One is a passion of being since it is predicated of being in the second mode of perseity; for although 'being' signifies what 'one' signifies, it does not signify this in the same way. Whatever 'being' signifies, it signifies positively and affirmatively rather than negatively. 'One', on the other hand, signifies all of the things signified by 'being' in both an affirmative and negative way. This is clear from the definition expressing the meaning of the word.
'One' has several senses; for as the philosopher indicates in the fifth Book of the Metaphysics, some things are said to be one essentially and others accidentally.! This should be understood to mean that the name 'one' is predicated of some things per se (i.e., in such a way that the proposition in which 'one' is predicated is a per se proposition) and that it is predicated of other things per accidens (i.e., in such a way that the proposition in which 'one' is predicated is a per accidens proposition). Thus the proposition 'Coriscus and the musical man are one' is per accidens, as is the proposition 'The just man and the musical man are one'. Nonetheless, the following propositions 'The just man and the musical man are per se one' and 'Coriscus and the musical man are per se one' are true, If one should run up against propositions like
'The musical man and the white man are per accidens one' and 'The musical man is per accidens one with Coriscus', he should construe them to mean
'The proposition "The musical man and the white man are one" is per accidens' and 'The proposition "The musical man is one with Coriscus" is per accidens'. Later I will show how these propositions can be distinguished.
That is essentially one which is not said to be one per accidens but per se; although the Philosopher posits many forms of per se unity in the fifth book of the Metaphysics, we need only consider the three forms of per se unity that logicians frequently employ.
Some things are said to be numerically one; that is, of terms which supposit for one and the same thing; the expression 'numerically one' is truly predicable. Examples are 'That man and Socrates are numerically one' and "1015
"Marcus and Tullius are numerically one'. Thus when Aristotle says in the fifth book of the Metaphysics, that "Things are numerically one which are one in matter," he only means that things are said to be numerically one when they are not distinct either in their matter or in their form.?
Further, those things are said to be specifically one for which there is one and the same species. Thus, things specifically one are always either numerically many or numerically one. As Aristotle says in the first book of the Topics, 'Things are specifically the same which, while being many,"
(supply here, if they are not numerically one) "are contained under the same species."® Finally, those things are generically one which are contained in the same genus. Things that are generically one are either both specifically and numerically many or they are specifically one. Aristotle says, "Things that are numerically one are always specifically one; but things that are specifically one are not, all of them, numerically one. Likewise, things specifically one are always generically one, but things that are generically one are not all specifically one."* From these remarks it follows that nothing is specifically one unless it is either numerically one or many. Consequently, it is impossible that there be a nature that is specifically one and neither numerically one nor many.
Similarly, it is impossible that there be a nature that is generically one without being either specifically one or many. Therefore, it should be said that many individuals are specifically one and that one individual is specifically the same as another individual. Likewise, many individuals of different species are generically one, and an individual of one species is generically one with another individual of another species. Socrates and the donkey are generically one, that is, there is one genus capable of being predicated of both.
Similarly, Socrates and Plato are specifically one; they are contained under one species. Put in another way Socrates and Plato are such that we can abstract from them one species common to both.
To the objection that Socrates and Plato are not really one, one should reply that they are really one provided that the term 'one' is being used in the appropriate sense—to mean one in species; for Socrates and Plato really are things such that one species can be abstracted from them. Thus, it should be granted that there is a form of unity less restrictive than numerical unity.
Nonetheless, each of those things are one in a sense in which it is impossible that they are one with anything that is in any way distinct from them.