We proceed to the first article thus:

1. It seems that to believe is not to think with assent. For "to think" implies inquiry of some kind, the word being a contraction of "to consider together" (cogitare = coagitare = simul agitate). But the Damascene says that "faith is assent without inquiry" (4 De Fid. Orth.1). It follows that the act of faith does not involve thinking.

2. Again, it will be shown in Q.4, Art.2, that faith belongs to reason. But it was said in Pt. I, Q.78, Art.4, that thinking is an act of the cogitative power, which belongs to the sensitive part of the soul. [52] It follows that faith does not involve thinking.

3. Again, belief is an act of the intellect, since the object of belief is the true. Now it was said in 12ae, Q.15, Art.1, ad.3 that assent is not an act of the intellect, but an act of the will, just as consent is an act of the will. It follows that to believe is not to think with assent.

On the other hand: "to believe" is thus defined by Augustine. {De Praed. Sanct.2.)

I answer: "to think" can mean three things. Firstly, it means any deliberative intellectual act in general. This is what Augustine has in mind in 14 De Trin.7, when he says: "what I now call understanding is that whereby we understand when we think." Secondly, and more precisely, it means the kind of intellectual deliberation which involves a degree of questioning, and which occurs before the intellect reaches perfection through the certainty of vision. This is what Augustine has in mind in 15 De Trin.16, where he says: "The Son of God is not called the Thought of God, but the Word of God. When our thought has reached what we know and become formed by it, it becomes our word. The Word of God should therefore be conceived as without the thought of God, since it contains nothing which remains to be formed, and which could be unformed." In this sense, thought properly means the movement of a soul which deliberates, and which is not yet perfected by a full vision of the truth. But since such movement may be either deliberation about universal meanings, which are the concern of the intellect, or deliberation about particular meanings, which are the concern of the sensitive part of the soul, the word "to think" is used in this second sense to mean the intellectual act of deliberation, and in yet a third sense to mean an act of the cogitative power.

Now if "to think" is understood in the first or general sense, "to think with assent" does not express the whole meaning of "to believe." For a man thinks in this way even about what he knows and understands in science, and also gives his assent. But if it is understood in the second sense, then by means of this expression we understand the whole nature of the act of belief. There are some acts of the intellect, such as those whereby one contemplates what one knows and understands in science, in which assent is given with confidence, without any deliberation. There are also others in which thought is unformed, and in which there is no firm assent. One may incline to neither alternative, as one who doubts. Or one may incline to the one rather than to the other on the strength of slight evidence, as does one who suspects. Or, again, one may choose one alternative with misgivings about the other, as does one who holds an opinion. Now the act which is "to believe" holds firmly to the one alternative. In this respect, belief is similar to science and understanding. Yet its thought is not perfected by clear vision, and in this respect belief is similar to doubt, suspicion, and opinion. To think with assent is thus the property of one who believes, and distinguishes the act of "belief" from all other acts of the intellect which are concerned with truth or falsity.

On the first point: faith does not make use of inquiry by natural reason to demonstrate what it believes. But it does inquire into the evidence by which a man is induced to believe, for example, into the circumstance that such things are spoken by God and confirmed by miracles.

On the second point: as we have said above, the word "to think" is here understood as it applies to the intellect, not as meaning an act of the cogitative power.

On the third point: the intellect of the believer is determined by the will, not by reason. Hence assent is here understood to mean the act of the intellect as determined by the will.

[52] The sensitive power operates through a corporeal organ, through which it perceives things which are actually present. The cogitative power perceives and preserves the "intention" or practical significance of particular things present or absent, by means of collating ideas. It is also called the "particular reason."