Thomas Aquinas

“ Thus it is that, as everything desires the perfection of its nature, intellectual nature desires naturally to be happy. Now that which is most perfect in any intellectual nature is the intellectual operation, by which in some sense it grasps everything. Whence the beatitude of every intellectual nature consists in understanding. Now in God, to be and to understand are one and the same thing; differing only in the manner of our understanding them. Beatitude must therefore be assigned to God in respect of His intellect ”

“ It seems that God is not called blessed in respect to His intellect. For beatitude is the highest good. But good is said to be in God in regard to His essence, because good has reference to being which is according to essence, according to Boethius (De Hebdom.) . Therefore beatitude also is said to be in God in regard to His essence, and not to His intellect. ”

“ Beatitude, as regards its object, is the supreme good absolutely, but as regards its act, in beatified creatures it is their supreme good, not absolutely, but in that kind of goods which a creature can participate. ”