I. Certain Notions concerning the Lower or Animal Psychic Life

422. - 1. In the higher or rational psychic life, right philosophy, departing from Cartesian tenets, recognizes only a twofold faculty: intellect and will, or rational cognition and appetite; but the third, which was called the affective faculty or affection (le sentiment), some judge to pertain to the intellect and others to the will.

Moreover, in the lower psychic life, three things occur which are observed distinctly: sensations or sensitive apprehensions; affections, agreeable or disagreeable, resulting therefrom; and appetite, or tendencies of pursuit or aversion. Modern authors also reduce these three to two. But, inquiring more into what appears simple or irreducible and what composite, they are accustomed to exhibit both of the former things as simple: sensations and affections, while they contend that appetite can be resolved into each of the two preceding elements. Classical philosophy, however, looking more to active faculties, instead refers all things to apprehension and appetite. In pleasure or the contrary affection there intervene: a) conjunction with good or evil, as the proximate cause of an agreeable or disagreeable affection; b) perception of this conjunction; c) the consequent complacency or displeasure. But whether pleasure or the contrary affection is formally in apprehen- sion or in appetite: concerning this matter the Scholastics dispute, and St. Thomas himself seems to have varied. Cf. De veritate, question 26, article 4, reply to objection 4; In tertium Sententiarum, distinction 15, question 2, article 3, solution 2; Summa theologica, I-II, question 35, article 1. Concerning this matter cf. Froebes, Lehrbuch der experimentellen Psychologie, vol. 1, pp. 24, 197, 198; vol. 2, p. 425, no. 2.

2. In order that we may say a few things concerning the individual elements: sensations are distinguished into three genera, according to physiologists: external sensations, so called from their object or cause by which they are determined, for example by contact; kinesthetic sensations, that is, those by which we are chiefly informed concerning the position and movement either of the body itself or of the members in their mutual relation (cf. Froebes, in the cited work, vol. 1, p. 145); organic sensations, which are excited by a change in the internal organs and teach us the state of the organism, but especially warn us concerning disturbed functions of vegetative life, as concerning poorly digested foods, visceral obstruction, hunger, thirst, and fatigue.

3. Affection or affective state designates the state and condition of the subject within himself, or the manner in which he experiences himself to be, whence we say: I am - or, I feel - well or ill.

Affection is accustomed to be joined with sensations, whether it accompanies them or results from them: thus a healthy man experiences the sense of agreeable satiety if, within the limits of temperance, he consumes good and pleasant foods. Nevertheless, it can sometimes subsist independently of sensations. Thus, with the will commanding, or with a cause of great joy dominating, someone in the midst of sensible pain can judge himself to be well or well affected, just as, on the contrary, moral sorrows can impede the efficacy of agreeable sensations. Therefore, between affection and sensations there prevail laws of association and mutual influence.

Most authors today, at least when there is discussion of lower psychology, distinguish only two specifically diverse affections: that of pleasantness or that of discomfort (jouissance, bien-être, ou malaise, indisposition). Nevertheless, not a few, with Wundt, recognize several pairs of affections: of excitation and quiet; of tension and relaxation.

The more vehement affections produce physiological changes of the internal organs, which changes in turn produce sensations and partial affections connected with them. Thus sadness of soul removes hunger and brings indigestion of the stomach, which itself also changes our affection.

Several partial affections - according to not a few physiologists, even if they are contrary - are accustomed to flow together into a resultant sum which is called the total affection. But the total affection arising from the cooperation of all organic sensations, or the affection of our body taken as a whole, is called the general or common affection.

4. Appetite is the act by which the subject is borne toward an apprehended good, whether present or absent. In the lower appetite the tendency is spontaneous; upon it, from instinct, there follows, likewise spontaneously, an exterior pursuit or flight: instinctive directions are less defined in man.