fection of
the intellect, namely, happiness, does not consist in God being seen
in His Essence.

Obj. 2: Further, the higher the perfection belongs to the higher
nature. But to see His own Essence is the perfection proper to the
Divine intellect. Therefore the final perfection of the human
intellect does not reach to this, but consists in something less.

_On the contrary,_ It is written (1 John 3:2): "When He shall appear,
we shall be like to Him; and [Vulg.: 'because'] we shall see Him as
He is."

_I answer that,_ Final and perfect happiness can consist in nothing
else than the vision of the Divine Essence. To make this clear, two
points must be observed. First, that man is not perfectly happy, so
long as something remains for him to desire and seek: secondly, that
the perfection of any power is determined by the nature of its
object. Now the object of the intellect is "what a thing is," i.e.
the essence of a thing, according to _De Anima_ iii, 6. Wherefore the
intellect attains perfection, in so far as it knows the essence of a
thing. If therefore an intellect knows the essence of some effect,
whereby it is not possible to know the essence of the cause, i.e. to
know of the cause "what it is"; that intellect cannot be said to
reach that cause simply, although it may be able to gather from the
effect the knowledge that the cause is. Consequently, when man knows
an effect, and knows that it has a cause, there naturally remains in
the man the desire to know about the cause, "what it is." And this
desire is one of wonder, and causes inquiry, as is stated in the
beginning of the _Metaphysics_ (i, 2). For instance, if a man,
knowing the eclipse of the sun, consider that it must be due to some
cause, and know not what that cause is, he wonders about it, and from
wondering proceeds to inquire. Nor does this inquiry cease until he
arrive at a knowledge of the essence of the cause.

If therefore the human intellect, knowing the essence of some created
effect, knows no more of God than "that He is"; the perfection of
that intellect does not yet reach simply the First Cause, but there
remains in it the natural desire to seek the cause. Wherefore it is
not yet perfectly happy. Consequently, for perfect happiness the
intellect needs to reach the very Essence of the First Cause. And
thus it will have its perfection through union with God as with that
object, in which alone man's happiness consists, as stated above (AA.
1, 7; Q