Previous PageTable Of ContentsNext Page

Porphyry, On the faculties of the Soul (1988) pp.75-82


On the Faculties of the Soul 1

[Translated by Kenneth Sylvan Guthrie]

Object of the Book 

We propose to describe the faculties of the soul, and to set forth the various opinions of the subject held by both ancient and modern thinkers.

Difference Between Sensation and Intelligence 

Aristo [there were two philosophers by this name, one a Stoic, the other an Aristotelian] attributes to the soul a perceptive faculty, which he divides into two parts. According to him, the first, called sensibility, the principle and origin of sensations, is usually kept active by one of the sense-organs. The other, which subsists by itself, and without; organs, does not bear any special name in beings devoid of reason, in whom reason does not manifest, or ac least manifests only in a feeble or obscure manner; however, it is called intelligence in beings endowed with reason, among whom done it manifests clearly. Aristo holds that sensibility acts only with the help of the sense-organs, and that intelligence does not need them, to enter into activity. Why then does he subordinate both of these to a single genus, called the perceptive faculty? Both doubtless perceive, but the one perceives the sense-form of beings, while the other perceives their essence. Indeed, sensibility does |76 not perceive the essence, but the sense-form, and the figure; it is intelligence that perceives whether the object be a man or a horse. There are, therefore, two kinds of perception that are very different from each other: sense-perception receives an impression, and applies itself to an exterior object, while intellectual perception does not receive an impression.

There have been philosophers who separated these two parts. They called intelligence or discursive reason the understanding which is exercised without imagination and sensation; and they called opinion the understanding which is exercised with imagination and sensation. Others, on the contrary, considered rational being, or nature, a simple essence, and attributed to it operations whose nature is entirely different. Now it is unreasonable to refer to the same essence faculties which differ completely in nature; for thought and sensation could not depend on the same essential principle, and if we were to call the operation of intelligence a perception, we would only be juggling with words. We must, therefore, establish a perfectly clear distinction between these two entities, intelligence and sensibility. On the one hand, intelligence possesses a quite peculiar nature, as is also the case with discursive reason, which is next below it. The function of the former is intuitive thought, while that of the latter is discursive thought. On the other hand, sensibility differs entirely from intelligence, acting with or without the help of organs; in the former case, it is called sensation, in the latter, imagination. Nevertheless, sensation and imagination belong to the |77 same genus. In understanding, intuitive intelligence is superior to opinion, which applies to sensation or imagination; this latter kind or thought, whether called discursive thought, or anything else [such as opinion], is superior to sensation and imagination, but inferior to intuitive thought.

On the Parts of the Soul.

It is not only about the faculties that the ancient philosophers disagree... They are also in radical disagreement about the following questions: What are the parts of the soul? What is a part? What is a faculty? What difference is there between a part and a faculty?

The Stoics divide the soul into eight parts: the five senses, speech, sex-power, and the directing [predominating] principle, which is served by the other faculties, so that the soul is composed of a faculty that commands, and faculties that obey.

In their writing about ethics, Plato and Aristotle divide the soul into three parts. This division has been adopted by the greater part of later philosophers; but these have not understood that the object of this definition was to classify and define the virtues (Plato: reason, anger and appetite; Aristotle: locomotion, appetite and understanding). Indeed, if this classification be carefully scrutinized, it will be seen that it fails to account for all the faculties of the soul; it neglects imagination, sensibility, intelligence, and the natural faculties (the generative and nutritive powers).

Other philosophers, such as Numenius, do not teach |78 one soul in three parts, like the preceding, nor in two, such as the rational and irrational parts. They believe that we have two souls, one rational, the other irrational. Some among them attribute immortality to both of the souls; others attribute it only to the rational soul, and think that death not only suspends the exercise of the faculties that belong to the irrational soul, but even dissolves its being or essence. Last, some believe that, by virtue of the union of the two souls, their movements are double, because each of them feels the passions of the other.

On the Difference of the Parts, and on the Faculties of the Soul 

We shall now explain the difference between a part and a faculty of the soul. One part differs from another by the characteristics of its genus (or kind), while different faculties may relate to a common genus. That is why Aristotle did not allow that the soul contained parts, though granting that it contained faculties. Indeed, the introduction of a new part changes the nature of the subject, while the diversity of faculties does not alter its unity. Longinus did not allow in the animal [or, living being] for several parts, but only for several faculties. In this respect, he followed the doctrine of Plato, according to whom the soul, in herself indivisible, is divided within bodies. Besides, that the soul does not have several parts does not necessarily imply that she has only a single faculty; for that which has no parts may still possess several faculties. |79 

To conclude this confused discussion, we shall have to lay down a principle of definition which will help to determine the essential differences and resemblances that exist either between the parts of the same subject, or between its faculties, or between its parts and its faculties. This will clearly reveal whether in the organism the soul really has several parts, or merely several faculties, and what opinion about them should be adopted. [For there are two special types of these.] The one attributes to man a single soul, genuinely composed of several parts, either by itself, or in relation to the body. The other one sees in man a union of several souls, looking on the man as on a choir, the harmony of whose parts constitutes its unity, so that we find several essentially different parts contributing to the formation of a single being.

First we shall have to study within the soul the differentials between the part, the faculty and the disposition. A part always differs from another by the substrate, the genus and the function. A disposition is a special aptitude of some one part to carry out the part assigned to it by nature. A faculty is the habit of a disposition, the power inherent in some part to do the thing for which it has a disposition. There was no great inconvenience in confusing faculty and disposition; but there is an essential difference between part and faculty. Whatever the number of faculties, they can exist within a single "being," or nature, without occupying any particular point in the extension of the substrate, while the parts somewhat participate in its extension, occupying |80 therein a particular point. Thus all the properties of an apple are gathered within a single substrate, but the different parts that compose it are separate from each other. The notion of a part implies the idea of quantity in respect to the totality of the subject. On the contrary, the notion of a faculty implies the idea of totality. That is why the faculties remain indivisible, because they penetrate the whole substrate, while the parts are separate from each other because they have a quantity.

How then may we say that a soul is indivisible, while having three parts? For when we hear it asserted that she contains three parts in respect to quantity, it is reasonable to ask how the soul can simultaneously be indivisible, and yet have three parts. This difficulty may be solved as follows: the soul is indivisible insofar as she is considered within her "being," and in herself; and that she has three parts insofar as she is united to a divisible body, and that she exercises her different faculties in the different parts of the body. Indeed, it is not the same faculty that resides in the head, in the breast, or in the liver2 [the seats of reason, of anger and appetite]. Therefore, when the soul has been divided into several parts, it is in this sense that her different functions are exercised within different parts of the body.

Nicholas [of Damascus],3 in his book On the Soul, used to say that the division of the soul was not founded on quantity, but on quality, like the division of an art or a science. Indeed, when we consider an extension, we see that the whole is a sum of its parts, and that it increases or diminishes according as a part is added or subtracted. |81 

Now it is not in this sense that we attribute parts to the soul; she is not the sum of her parts, because she is neither an extension nor a multitude. The parts of the soul resemble those of an art. There is, however, this difference, that an art is incomplete or imperfect if it lacks some part, while every soul is perfect, and while every organism that has not achieved the goal of its nature is an imperfect being.

Thus by parts of the soul Nicholas means the different faculties of the organism. Indeed, the organism and, in general, the animated being, by the mere fact of possessing a soul, possesses several faculties, such as life, feeling, movement, thought, desire, and the cause and principle of all of them is the soul. Those, therefore, who distinguish parts in the soul thereby mean the faculties by which the animated being can produce actualizations or experience affections. While the soul herself is said to be indivisible, nothing hinders her function from being divided. The organism, therefore, is divisible, if we introduce within the notion of the soul that of the body; for the vital functions communicated by the soul to the body must necessarily be divided by the diversity of the organs, and it is this division of vital functions that has caused parts to be ascribed to the soul herself. As the soul can be conceived of in two different conditions, according as she lives within herself, or as she declines towards the body,4 it is only when she declines towards the body that she splits up into parts. When a seed of corn is sowed and produces an ear, we see in this ear of corn the appearance of parts, though the whole it forms is |82 indivisible,5 and these indivisible parts themselves later return to an indivisible unity; likewise, when the soul, which by herself is indivisible, finds herself united to the body, parts are seen to appear.

We must still examine the faculties that the soul develops by herself [intelligence and discursive reason], and which the soul develops by the animal [sensation]. This will be the true means of illustrating the difference between these two natures, and the necessity of reducing to the soul herself those parts of her being which have been enclosed within the parts of the body.6


1)  Stobaeus, Eclogae Physicae, 1.52, ed. Heeren.

2)  See Ennead IV.3.23.

3)  In his book On the Soul.

4) See Ennead 1.1.12.

5) See Ennead II.6.1.

6) See Ennead 1.1.


Previous PageTable Of ContentsNext Page

This text was transcribed by Roger Pearse, 2007. All material on this page is in the public domain - copy freely.  The text was found in Porphyry's Launching-Points to the Realm of Mind, taken from the 1988 reprint.


Early Church Fathers - Additional Texts