tellect is an individual, and so is yours; for individuals are
things which differ in number but agree in one species. Now whatever
is received into anything must be received according to the condition
of the receiver. Therefore the species of things would be received
individually into my intellect, and also into yours: which is
contrary to the nature of the intellect which knows universals.

Obj. 4: Further, the thing understood is in the intellect which
understands. If, therefore, my intellect is distinct from yours, what
is understood by me must be distinct from what is understood by you;
and consequently it will be reckoned as something individual, and be
only potentially something understood; so that the common intention
will have to be abstracted from both; since from things diverse
something intelligible common to them may be abstracted. But this is
contrary to the nature of the intellect; for then the intellect would
seem not to be distinct from the imagination. It seems, therefore, to
follow that there is one intellect in all men.

Obj. 5: Further, when the disciple receives knowledge from the
master, it cannot be said that the master's knowledge begets
knowledge in the disciple, because then also knowledge would be an
active form, such as heat is, which is clearly false. It seems,
therefore, that the same individual knowledge which is in the master
is communicated to the disciple; which cannot be, unless there is
one intellect in both. Seemingly, therefore, the intellect of the
disciple and master is but one; and, consequently, the same applies
to all men.

Obj. 6: Further, Augustine (De Quant. Animae xxxii) says: "If I were
to say that there are many human souls, I should laugh at myself."
But the soul seems to be one chiefly on account of the intellect.
Therefore there is one intellect of all men.

_On the contrary,_ The Philosopher says (Phys. ii, 3) that the
relation of universal causes to universals is like the relation of
particular causes to individuals. But it is impossible that a soul,
one in species, should belong to animals of different species.
Therefore it is impossible that one individual intellectual soul
should belong to several individuals.

_I answer that,_ It is absolutely impossible for one intellect to
belong to all men. This is clear if, as Plato maintained, man is the
intellect itself. For it would follow that Socrates and Plato are
one man; and that they are not distinct from each