Summa Theologica, Part I (Prima Pars) From the Complete...

Reply Obj. 3: The "scientific" part, of which the Philosopher speaks, is not the same as the higher reason: for necessary truths are found even among temporal things, of which natural science and mathematics treat. And the "opinionative" and "ratiocinative" part is more limited than the lower reason; for it regards only things contingent. Neither must we say, without any qualification, that a power, by which the intellect knows necessary things, is distinct from a power by which it knows contingent things: because it knows both under the same objective aspect—namely, under the aspect of being and truth. Wherefore it perfectly knows necessary things which have perfect being in truth; since it penetrates to their very essence, from which it demonstrates their proper accidents. On the other hand, it knows contingent things, but imperfectly; forasmuch as they have but imperfect being and truth. Now perfect and imperfect in the action do not vary the power, but they vary the actions as to the mode of acting, and consequently the principles of the actions and the habits themselves. And therefore the Philosopher postulates two lesser parts of the soul—namely, the "scientific" and the "ratiocinative," not because they are two powers, but because they are distinct according to a different aptitude for receiving various habits, concerning the variety of which he inquires.

Reply Obj. 4: That distinction given by Damascene is according to the variety of acts, not according to the variety of powers. For "opinion" signifies an act of the intellect which leans to one side of a contradiction, whilst in fear of the other. While to "judge" or "measure" [mensurare] is an act of the intellect, applying certain principles to examine propositions. From this is taken the word "mens" [mind]. Lastly, to "understand" is to adhere to the formed judgment with approval. _______________________

Objection 1: It would seem that the intelligence is another power than the intellect. For we read in De Spiritu et Anima that "when we wish to rise from lower to higher things, first the sense comes to our aid, then imagination, then reason, then intellect, and afterwards intelligence." But imagination and sense are distinct powers. Therefore also intellect and intelligence are distinct.

Obj. 2: Further, Boethius says (De Consol. v, 4) that "sense considers man in one way, imagination in another, reason in another, intelligence in another." But intellect is the same power as reason. Therefore, seemingly, intelligence is a distinct power from intellect, as reason is a distinct power from imagination or sense.

Obj. 3: Further, "actions came before powers," as the Philosopher says (De Anima ii, 4). But intelligence is an act separate from others attributed to the intellect. For Damascene says (De Fide Orth. ii) that "the first movement is called intelligence; but that intelligence which is about a certain thing is called intention; that which remains and conforms the soul to that which is understood is called invention, and invention when it remains in the same man, examining and judging of itself, is called phronesis (that is, wisdom), and phronesis if dilated makes thought, that is, orderly internal speech; from which, they say, comes speech expressed by the tongue." Therefore it seems that intelligence is some special power.

On the contrary, The Philosopher says (De Anima iii, 6) that "intelligence is of indivisible things in which there is nothing false." But the knowledge of these things belongs to the intellect. Therefore intelligence is not another power than the intellect.

I answer that, This word "intelligence" properly signifies the intellect's very act, which is to understand. However, in some works translated from the Arabic, the separate substances which we call angels are called "intelligences," and perhaps for this reason, that such substances are always actually understanding. But in works translated from the Greek, they are called "intellects" or "minds." Thus intelligence is not distinct from intellect, as power is from power; but as act is from power. And such a division is recognized even by the philosophers. For sometimes they assign four intellects—namely, the "active" and "passive" intellects, the intellect "in habit," and the "actual" intellect. Of which four the active and passive intellects are different powers; just as in all things the active power is distinct from the passive. But three of these are distinct, as three states of the passive intellect, which is sometimes in potentiality only, and thus it is called passive; sometimes it is in the first act, which is knowledge, and thus it is called intellect in habit; and sometimes it is in the second act, which is to consider, and thus it is called intellect in act, or actual intellect.

Reply Obj. 2: Boethius takes intelligence as meaning that act of the intellect which transcends the act of the reason. Wherefore he also says that reason alone belongs to the human race, as intelligence alone belongs to God, for it belongs to God to understand all things without any investigation.

Reply Obj. 3: All those acts which Damascene enumerates belong to one power—namely, the intellectual power. For this power first of all only apprehends something; and this act is called "intelligence." Secondly, it directs what it apprehends to the knowledge of something else, or to some operation; and this is called "intention." And when it goes on in search of what it "intends," it is called "invention." When, by reference to something known for certain, it examines what it has found, it is said to know or to be wise, which belongs to "phronesis" or "wisdom"; for "it belongs to the wise man to judge," as the Philosopher says (Metaph. i, 2). And when once it has obtained something for certain, as being fully examined, it thinks about the means of making it known to others; and this is the ordering of "interior speech," from which proceeds "external speech." For every difference of acts does not make the powers vary, but only what cannot be reduced to the one same principle, as we have said above (Q. 78, A. 4). _______________________

Objection 1: It would seem that the speculative and practical intellects are distinct powers. For the apprehensive and motive are different kinds of powers, as is clear from De Anima ii, 3. But the speculative intellect is merely an apprehensive power; while the practical intellect is a motive power. Therefore they are distinct powers.

Obj. 2: Further, the different nature of the object differentiates the power. But the object of the speculative intellect is truth, and of the practical is good; which differ in nature. Therefore the speculative and practical intellect are distinct powers.

Obj. 3: Further, in the intellectual part, the practical intellect is compared to the speculative, as the estimative is to the imaginative power in the sensitive part. But the estimative differs from the imaginative, as power form power, as we have said above (Q. 78, A. 4). Therefore also the speculative intellect differs from the practical.

I answer that, The speculative and practical intellects are not distinct powers. The reason of which is that, as we have said above (Q. 77, A. 3), what is accidental to the nature of the object of a power, does not differentiate that power; for it is accidental to a thing colored to be man, or to be great or small; hence all such things are apprehended by the same power of sight. Now, to a thing apprehended by the intellect, it is accidental whether it be directed to operation or not, and according to this the speculative and practical intellects differ. For it is the speculative intellect which directs what it apprehends, not to operation, but to the consideration of truth; while the practical intellect is that which directs what it apprehends to operation. And this is what the Philosopher says (De Anima iii, 10); that "the speculative differs from the practical in its end." Whence each is named from its end: the one speculative, the other practical—i.e. operative.

Reply Obj. 2: Truth and good include one another; for truth is something good, otherwise it would not be desirable; and good is something true, otherwise it would not be intelligible. Therefore as the object of the appetite may be something true, as having the aspect of good, for example, when some one desires to know the truth; so the object of the practical intellect is good directed to the operation, and under the aspect of truth. For the practical intellect knows truth, just as the speculative, but it directs the known truth to operation.

Objection 1: It would seem that "synderesis" is a special power, distinct from the others. For those things which fall under one division, seem to be of the same genus. But in the gloss of Jerome on Ezech. 1:6, "synderesis" is divided against the irascible, the concupiscible, and the rational, which are powers. Therefore "synderesis" is a power.

Obj. 2: Further, opposite things are of the same genus. But "synderesis" and sensuality seem to be opposed to one another because "synderesis" always incites to good; while sensuality always incites to evil: whence it is signified by the serpent, as is clear from Augustine (De Trin. xii, 12,13). It seems, therefore, that "synderesis" is a power just as sensuality is.

Obj. 3: Further, Augustine says (De Lib. Arb. ii, 10) that in the natural power of judgment there are certain "rules and seeds of virtue, both true and unchangeable." And this is what we call synderesis. Since, therefore, the unchangeable rules which guide our judgment belong to the reason as to its higher part, as Augustine says (De Trin. xii, 2), it seems that "synderesis" is the same as reason: and thus it is a power.

On the contrary, According to the Philosopher (Metaph. viii, 2), "rational powers regard opposite things." But "synderesis" does not regard opposites, but inclines to good only. Therefore "synderesis" is not a power. For if it were a power it would be a rational power, since it is not found in brute animals.

I answer that, "Synderesis" is not a power but a habit; though some held that it is a power higher than reason; while others [*Cf. Alexander of Hales, Sum. Theol. II, Q. 73] said that it is reason itself, not as reason, but as a nature. In order to make this clear we must observe that, as we have said above (A. 8), man's act of reasoning, since it is a kind of movement, proceeds from the understanding of certain things—namely, those which are naturally known without any investigation on the part of reason, as from an immovable principle—and ends also at the understanding, inasmuch as by means of those principles naturally known, we judge of those things which we have discovered by reasoning. Now it is clear that, as the speculative reason argues about speculative things, so that practical reason argues about practical things. Therefore we must have, bestowed on us by nature, not only speculative principles, but also practical principles. Now the first speculative principles bestowed on us by nature do not belong to a special power, but to a special habit, which is called "the understanding of principles," as the Philosopher explains (Ethic. vi, 6). Wherefore the first practical principles, bestowed on us by nature, do not belong to a special power, but to a special natural habit, which we call "synderesis." Whence "synderesis" is said to incite to good, and to murmur at evil, inasmuch as through first principles we proceed to discover, and judge of what we have discovered. It is therefore clear that "synderesis" is not a power, but a natural habit.

Reply Obj. 3: Those unchangeable notions are the first practical principles, concerning which no one errs; and they are attributed to reason as to a power, and to "synderesis" as to a habit. Wherefore we judge naturally both by our reason and by "synderesis." _______________________

Objection 1: It would seem that conscience is a power; for Origen says [*Commentary on Rom. 2:15] that "conscience is a correcting and guiding spirit accompanying the soul, by which it is led away from evil and made to cling to good." But in the soul, spirit designates a power—either the mind itself, according to the text (Eph. 4:13), "Be ye renewed in the spirit of your mind"—or the imagination, whence imaginary vision is called spiritual, as Augustine says (Gen. ad lit. xii, 7,24). Therefore conscience is a power.

Obj. 3: Further, conscience must of necessity be either an act, a habit, or a power. But it is not an act; for thus it would not always exist in man. Nor is it a habit; for conscience is not one thing but many, since we are directed in our actions by many habits of knowledge. Therefore conscience is a power.

I answer that, Properly speaking, conscience is not a power, but an act. This is evident both from the very name and from those things which in the common way of speaking are attributed to conscience. For conscience, according to the very nature of the word, implies the relation of knowledge to something: for conscience may be resolved into "cum alio scientia," i.e. knowledge applied to an individual case. But the application of knowledge to something is done by some act. Wherefore from this explanation of the name it is clear that conscience is an act.