VII. Psychology
Life is called soul by Aristotle, and is the form of organized matter, and the principle of immanent action. Consequently, living beings are distinguished from minerals, whose form is the principle of transient action.
Corresponding to the three hierarchical grades of living beings there are three forms of psychic life:
Vegetative life, proper to plants, whose operations are for the nourishment and growth of the plants themselves; Sensitive life, proper to animals, which, besides nutrition and growth, have also the faculty of locomotion and of sense; and Intellective life, proper to man, who, besides assuming the two inferior souls (vegetative and sensitive), has also the faculty of knowing through universal concepts.
Contrary to Plato, who affirmed that there are in man two distinct souls (one having two aspects) and that the union of the rational soul with the body is accidental, Aristotle vindicates the oneness of the soul, which is the form (entelechy) of the body and hence is immanent in it.
The various functions proper to the vegetative and sensitive life are performed by the one soul, which also has the capability of performing superior operations, of gaining knowledge through concepts (intellectual cognition).
Cognitive Activities
There are two cognitive activities of the soul, and these give origin to two distinct types of knowledge: sensible and intellective.
Sensible cognition, sensation, is objective and presupposes a physical fact, a contact of the object with an organ or sense of the subject, who then transforms the physical contact into a psychic act, or cognition of the object.
There are five senses, each of which perceives its proper sensible; the eye, for example, apprehends light; the taste, sapidity.
Aristotle calls common sensibles those qualities of the object that can be perceived by more than one sense organ -- size and shape, for instance, which can be perceived by the senses of sight and touch.
To the sensitive faculties belong also the memory (the faculty which preserves images already perceived) and the phantasy or imagination (the faculty which revives such images and represents them in the absence of the object itself).
The proper object of sensitive knowledge is the individual, the particular, the contingent and material thing.
The intellect, on the other hand, has as its object the universal, the necessary, the immutable, the essences, the forms of things abstracted from their individuation.
But for Aristotle the intellect does not possess innate ideas. Contrary to the innatism of Plato, Aristotle defends the theory of the tabula rasa (blank slate).
In its first awakening the intellect possesses no beautiful and formed ideas; it has only the capacity for receiving ideas, and acquires them by abstraction from the data of the senses. Sensation contains the universal concept "in potentia"; the intellect has the power of enucleating the universal.
We are now confronted with two potencies which of themselves cannot be the cause of the passage into act. Aristotle solves the difficulty by having recourse to an intellect which he calls poieticos, the agent intellect, in which the intelligible species is in act. This acts upon the so-called passive intellect (pateticos) and gives actuality to the concept contained in potency in the sensation.
Analogous to cognitive activity, there are also two practical activities of the soul: the appetite and the will. The appetite is a tendency toward a good presented by way of sensitive cognition and is proper to the animal soul. The will is the impulse toward a good guided by reason, and is proper to the rational soul.
The Immortality of the Soul
The question of the immortality of the human soul is one of the most obscure in the doctrine of Aristotle. It appears in fact that he affirms the immortality of the active intellect, which is one for all human beings; and denies it for the passive intellect, which is individual and the immanent form of the body.
On the other hand, Aristotle admits that the proper object of the soul is the knowledge of the universal, of the immaterial, of essences, and hence it is impossible to understand how the individual soul can perish with the body.
The steps in Aristotle's reasoning on this point are not clear, and thus his interpreters have divided them into opposing opinions.
VIII. Ethics
Ethics, for Aristotle, has the purpose of establishing what is the end that man, according to his nature, must attain, and also from what source his happiness comes.
The end of man, as for every being, according to the doctrine established in metaphysics, is the realization of the form, the attainment of the perfection due to his nature.
Now man is a rational animal, and hence his end will be the attainment of wisdom. The actions which bring one to the realization of this perfection of living according to reason are called virtues. Virtue, for Aristotle, is not the end, but the means to attain perfection, and consists in a conscious action fulfilled according to reason.
Aristotle distinguishes two types of virtue:
Dianoetical, and Ethical.
Dianoetical (dia-noetics) concerns the perfection of reason in itself and therefore pertains to such virtues as prudence and wisdom, which give us the absolute, metaphysical knowledge of nature and of the universe in which we must act.
In the determination of ethical virtues, Aristotle is in conformity with the whole of Greek Socratic-Platonic thought in which science or knowledge is virtue.
But Aristotle recognizes the fact that man is not pure reason, that he also has passions; that he is a rational animal. In this, Aristotle goes far beyond the simple Greek intellectualism of other philosophers.
The passions imply a sentimental, affective element, an organic tendency of our body. At variance with Plato, Aristotle says that these tendencies should not be considered an evil, and hence should not be annulled. If they are regulated by reason they concur in the realization of the form and perfection which are due to man because of his nature.
The ethical virtues concern the activity of the passions controlled by reason.
The ethical virtues, according to Aristotle, consist in a just mean between two extremes.
This just mean is not a sole and abstract rule, but is relative to circumstances. Thus between prodigality and avarice there is the just mean of generosity; between abstinence from and abuse of pleasures there is the mean of temperance. The rule of virtue is relative in so far as what for a poor man is generosity may for a rich man be avarice.
The ethical virtues include another element, constancy. One swallow, says Aristotle, does not make spring. (One performance of an action does not make a habit.) Thus it is not enough to perform one act of generosity in order to be generous; it is necessary to act constantly according to the dictates of reason.
Constancy induces what Aristotle calls habit, a constant right moral disposition. Habit is acquired by the repetition of acts. The ethical virtues are based on natural dispositions, and with assiduous repetition they become mechanical, so to speak; they become second nature.
In this way a habit of virtue or vice may be contracted through repeated acts of virtue or vice. It is thus clear that Aristotelian morality is essentially rational, a system which tends to organize all human activity according to reason.
Happiness consists in this rational activity. It can be lacking, and this absence can make a man poor, but not miserable.
