The greatest benefit to owning the Summa Theologica by St. Thomas Aquinas is not that you get to read it from front to back; cover to cover as it were. I can’t imagine a more grim prospect. I mean Aquinas is great, but that’s some fairly dense reading for a layman such as myself. No, the great benefit of owning the Summa is to have it as a handy reference anytime you want to see what Aquinas has to say on a particular subject. And what Aquinas has to say on any subject is worth reading.
This morning as I was perusing what Aquinas has to say on the subject of virtue, I was lead to see what he had to say on the subject of happiness. For virtue is that by which we fulfill our potential as man created in God’s image, and in practicing virtue man finds himself in a state of happiness as he slowly progresses toward that which is his final happiness – what Aquinas calls “perfect happiness.” So the question may be posed. In what does man’s happiness consist? What do we mean by a final state of perfect happiness? Here is how Aquinas answers (PII, Q3, A8):
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 of 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,7; Q, A).