Philosophy of intellect
Thomas Aquinas on potential
and active intellect
The spectrum of issues concerning human cognition introduced in this work has
been presented on the basis of the Aristotelian differentiation between two intellects,
potential and active. This differentiation was related to further domains of theoretical
philosophy which became a fundament of that what has been described as the philoso-
phy of the intellect. The philosophy of the intellect is a systematic presentation of these
metaphysical and theory of cognition issues, which on the basis of the Aristotelian
distinction are directly concerned with domain of intellect. According to the presented
research and its results, we assume that one cannot easily equate the philosophy of
intellect and the philosophy of mind, as it might result in the process of implementing
the enormous interpretative difficulties into the Thomistic understanding of the nature
of human being and its activities. Philosophy of intellect is a proper perspective then,
to conduct a further research on specific issues concerning human cognition. Further
research should consider both a practical aspect of activity of the human intellect,
domain we may call „the ethics of intellect”, and aspects strictly theological, which
might be called „the theology of intellect”.
In the first part the metaphysical issues concerning the nature of intellect has
been presented. On the one hand, it was shown what is the purpose in differentiating
intellects with regard to the fact of relating and belonging a human being to other
intellectual beings. In this part the metaphysical status of intellects as the properties
(proprietates) of soul has been stressed, and further, the dependence of intellects on
substantial form. The potential and active intellects are not only the aspects of human
cognition, whose differentiation is only a historical domain of low importance. Both
intellects constitutes the principles of human, and only human, activity. They in reality
differ in a way such as act differs from potentiality. They differ because man has both,
ability enabling cognition and ability to its entirely passive perception.
In the second part the fundamental issues concerning human cognition has been
presented in the light of the theory of two intellects. These issues consist of: relation
of intellect to sensual cognition, abstraction, understanding and judging, theory of
cognitive forms, identity of object with the cognizing intellect, the question of truth
located in the intellect, the problem of intuition, the problem of self- cognition (cogni-
tion of the self), and finally the issue of formation of the word. Solution of each of the
above issue in the thought of Aquinas depends on the prior, deepen understanding of
human intellect in which there is a particular place for the potential and active intellect.
Key statements included in the work, concerning the potential and active intellect,
might be gathered at the end and presented in the essential points.
At first, Thomas interpreted the text of Aristotle in a way that allows to say that
the potential and active intellects were related to a particular human being individually
and that they would enable the intellectual cognition in each particular case. Following
Aristotle, Thomas stressed immateriality of the potential intellect and being (existing)
in the act of the active intellect whose power is not of absolute character and is strictly
related with introducing the intelligible structure in cognition with regard to that what
is material and sensually cognizable. Determination worked out by the Peripathetic
tradition regarding the intellect in the act, the acquired intellect, the improved intellect
served to describe the nature of the potential intellect.
Secondly, the differentiation between the potential and active intellect describing
the nature of human being as the intellectual one has been related with the under-
standing of the hierarchy in beings, especially with relating human being to beings
of the intellectual nature. Man, for the fact that it falls to the domain of intellectual
beings, has the lowest of the intellects within intellectual beings, the intellect in the
possibility to cognize and acquire forms from the sensual objects. In the result, its
access to cognize things within its own order is impeded.
Thirdly, the potential and active intellects are not of subsistent character and
their form designates them to be an area of powers (possibilities), which determine
the acts of taking place the immaterial acts of cognition. Soul as substantial form is,
according to Thomas, both a subsistent form, which means that is strictly united with
body, and it also is independent from body in its (soul’s) functions and existence. The
fact that Thomas calls the intellect the form of body was an expression of his intention
to object to Averroism and in that way stressing the individual nature of both intellects
related with the particular human being. They are related to each particular man to
the extend they condition the fact that hic homo intelligit.
The fourth issue is that the potential intellect and the active intellect differ as two
powers with regard to acts they proceed and with regard to objects which condition
precisely these specific acts, not the other ones. Differentiation between them is not
only the process of applying different functions to them, but presenting them as actually
different powers. Denoting the potential intellect as a passive power, and the active
intellect as an active power, enabled to understand them as the faculties of substance,
and at the same time, as their specific kind- properties (proprietates). For denoting the
potential intellect Aquinas employs various names, it is that what denotes phrases like:
the theoretical intellect and the practical, intelligence, reason, memory, higher and lower
reason, conscience and synderesis and mind. The potential intellect is that whose nature
(possibility) is decisive for justifying immateriality. The impediment argument appeals
to the intellect in quo omnia fiunt. At the same time however, the human intellect is
not determined to anything proper to its own area. The potential and active intellects
could be called the mind on the strict specific conditions. The mind is a name which
either should specify the will or should specify the act of both intellects which means
„measuring” things according to cognitive principles. The term mind may also designate
the intellectual soul (mind) from which its highest powers, ascribed to it, will result.
The fifth, the potential and active intellect are differentiated with regard to the
object of activity which is an essence of material things, cognizable within a frame of
that what is cognizable sensually. In describing the nature of the potential intellect we
turn to negation of any prior understandings which could have exceeded cognition and
conditioned it. The proper activity of the intellect is abstraction. It is both demateriali-
sation of the imagined thing and the turning the subject of the intellectual cognition,
which is in a state of possibility toward cognition, into an object which actually acts
on the potential intellect. Assessing the intellectual structure (generality and necessity)
of that is cognizable sensually is on the part of the active intellect (agit sibi simile). In
this sense we can admit that the character of active intellect is such that it can form
that what is cognized and what further form the potential intellect. Abstraction is
not introducing a content into what is cognized, it is rather the process of unveiling
the essential parts of the cognized being. The proper activity of the potential intellect
is the „understanding that what is undivided” and „joining and dividing” which are
expressed in simple acts of understanding things and formulating judgements. Analysis
of these acts shows the potential intellect as that which is in a natural way directed
toward cognizing the essence and the existence, accompanied with the activity of the
active intellect.
The sixth is that the intellectual cognitive forms (species intelligibiles) explain
cognition as far as they show a relation between the cognized thing, the influence
(operating) of the active intellect on the imagination and on their perception in the
potential intellect. The active intellect adapts the sensual cognitive form in such a way
that it can be grasped by the potential intellect, without altering the content of the
object in no way. From the perspective of the potential intellect the cognitive forms
remain that what is the condition for the object to be cognized (medium quo), they are
not that on what the intellect focus its attention (medium quod). The potential intellect
which adopted a cognitive form becomes a thing cognizable in the act. Species intelli-
gibilis actualizes the human intellect in a way that it gains a perfection and fulfillment
of cognition. The act of the intellectual cognition expresses the formal identity of the
cognizing subject, the cognized object and the intellect in the act (intellectus in actu),
which in uniting with form cognizes in a thing all that the thing is consisted of.
The seventh issue. The potential and active intellects explains the Thomistic un-
derstanding of truth. The potential intellect while cognizing a thing (which posseses
a property of truth for the very fact of existence) remains in relation with it, a relation
which can be assumed in the act of judgement and further either accepted or rejected.
The essence of truth (ratio veritatis) is expressed through, stressed by Aquinas, a strict
dependence of the existing being and the intellect cognizing it. And although the hu-
man intellect measures the existed thing, it itself is antecedently measured by the thing.
The eight. Intuition is an activity of the potential and active intellect as far as it
cognizes its object non-discoursively. Intuition then, is strictly related to the first act
of the intellect in which „the understanding of that what is undivided” takes place.
The intellectual cognition (intuitive) is described by Thomas as an act of „reading the
interior of a thing” and also of the „reading in the interior of a thing”. In both cases
cooperation of the potential and active intellect is expressed through cognition of the
essence and existence of things.
The ninth. The acts taking place in the potential and active intellects decide on
cognition of the self. The intellectual cognition of the self is conditioned by activities
of two intellects – both when the actual self-knowledge is concerned, cognition of the
self through the acts undertaken, habitual self- knowledge and the self-knowledge
ravealing itself in each cognition according to the first principles.
The tenth. The moment of formation of the word in the intellect shows the
nature of the intellect. It not only passively adopts the form, but also expresses the
understandings (intellectum). The word in the intellect expresses and reveals the prior
acts of the intellect, what means that it is the end of the intellectual activities, and
also the beginning (principium) of any other volitional relations towards existing and
cognized reality.
Thomas’ conception of the intellectual cognition is grounded in the differentia-
tion between two intellects, and their actions and improvements reveal the nature of
human being, which belongs (however in an impaired mode) to the intellectual beings.
The topic of two intellectual powers, or rather the most important cognitive abilities
of human being, was for Thomas as much important as the problem of being in which
he constantly seen the essence and the existence as separated. Hence, the small error
concerning the principles of being was for Aquinas of general importance, for the
understanding of reality, and the small error concerning the intellectual domain in
human being is decisive for the understanding of reality and the human being itself.
