We proceed to the third article thus:

1. It seems that by charity God is to be loved not on account of himself, but on account of what is other than himself. For Gregory says in a homily (Hom. in Evang.11): "the soul learns to love the unknown from the things which it knows." Now by the unknown he means intelligible and divine things, and by the known he means the things of sense. Hence God is to be loved on account of things other than himself.

2. Again, according to Rom.1:20: "the invisible things of him . . . are clearly seen, being understood by the things that are made," love to God is consequential. Hence God is loved on account of what is other than himself, not on account of himself.

3. Again, the gloss (on Matt.1:2: "Abraham begat Isaac") says that "hope begets charity," and Augustine (Tract.9 in Joan.) says that "fear begets charity." Now hope expects to receive something from God, and fear shrinks from something that God might inflict. It seems, then, that God is to be loved either on account of some good for which we hope, or on account of some evil which we fear. It follows that God is not to be loved on account of himself.

On the other hand: Augustine says (1 De Doctr. Christ.4) that "to enjoy someone is to cling to him on account of himself," and he also says that "God is to be enjoyed." It follows that God is to be loved on account of himself.

I answer: "on account of" denotes a causal relation. But there are four kinds of cause -- final cause, formal cause, efficient cause, and material cause. [75] A material disposition is reducible to a material cause, since it is a cause conditionally only, not absolutely. We can thus affirm that one thing is to be loved "on account of" another according to each of these four kinds of cause. We love medicine, for example, on account of health as a final cause. We love a man on account of virtue as a formal cause, since by reason of virtue he is formally good, and consequently lovable. We love some persons on account of their being the sons of a certain father, which circumstance is the efficient cause of our love. We are also said to love a person on account of something which disposes us to love him, such as benefits received from him, this being a material disposition reducible to a material cause. Once we have begun to love a friend, however, we love him not on account of such benefits, but on account of virtue.

Now in each of the first three of these senses we love God on account of himself, not on account of what is other than himself. For God does not serve anything other than himself as a final end, but is himself the final end of all things. Neither is God formally good by reason of anything other than himself. For his own substance is his goodness, and his goodness is the exemplary form by which all things are good. Nor, again, is goodness in God through another, but in all things through God. In the fourth sense, however, God can be loved on account of what is other than himself. For we are disposed to love God the more on account of other things, such as benefits received, or rewards for which we hope, or even the punishments which we hope to avoid through him.

On the first point: this quotation, "the soul learns to love the unknown from the things which it knows," does not mean that the known is the formal, final, or efficient cause of love for the unknown. It means that one is disposed by what one knows to love the unknown.

On the second point: knowledge of God is acquired through other things. But once God is known, he is known not through other things, but through himself, in accordance with John 4:42: "Now we believe, not because of thy saying; for we have heard him ourselves, and know that this is indeed . . . the Saviour of the world."

On the third point: hope and fear lead to charity by way of a certain disposition.

[75] Cf. Aristotle's Physics, bk. 2, ch. 3 (194b); ch. 7 (198a); Metaphysics A, ch. 3 (983a); D, ch. 2 (1013a-b). The final cause is the end for the sake of which a thing is. The formal cause is the formula for the essence of a thing. The efficient cause is the source of the change through which a thing comes to be what it is. The material cause is the material element out of which a thing is made.