Neither can perfect beatitude consist in knowledge of the higher, entirely immaterial, or, as Thomas calls them, separate (separatae) substances, to wit, the Angels. Because it cannot consist in that which is the perfection of intelligence only from participation. The object of the intelligence is the true. Whatever has truth only through participation in something else cannot make the contemplating intelligence perfect with a final perfection. But the angels have their being (esse) as they have their truth, from the participation of the divine in them. Whence it remains that only the contemplation of God, Who alone is truth through His essential being, can make perfectly blessed. "But," adds Thomas, "nothing precludes the expectation of some imperfect beatitude from contemplating the angels, and even a higher beatitude than lies in the consideration of the speculative sciences."
So the conclusion is that "the final and perfect beatitude can be only in the vision of the divine essence. The proof of this lies in the consideration of two matters: first, that man is not perfectly blessed (beatus) so long as there remains anything for him to desire or seek; secondly, that the perfection of every capacity (potentiae), is adjudged according to the nature (ratio) of its object." And a patent line of argument leads to the unavoidable conclusion: "For perfect beatitude it is necessary that the intellect should attain to the very essence of the first cause. And thus it will have its perfection through union with God as its object."
There are few novel thoughts in Thomas's conception of man's supreme beatitude. But he has taken cognizance of all pertinent considerations, and put the whole matter together with stable coherency. He continues,discussing in the succeeding Quaestiones a number of important matters incidental to his central determination of the nature of man's supreme good. Thus he shows how joy (delectatio) is a necessary accompaniment of beatitude, which, however, in principle consists in the action of the mind, which is visio, rather than in the resulting delectatio. The latter consists in a quieting or satisfying of the will, through the goodness of that in which it is satisfied. When the will is satisfied in any action, that results from the goodness of the action; and the good lies
