Nous (UK: /naʊs/,[1] US: /nuːs/), from Greek: νοῦς, is a concept from classical philosophy, sometimes equated to intellect or intelligence, for the faculty of the human mind necessary for understanding what is true or real.
In Aristotle's philosophy, which was influential on later conceptions of the category, nous was carefully distinguished from sense perception, imagination, and reason, although these terms are closely inter-related.
Such explanations were influential in the development of medieval accounts of God, the immortality of the soul, and even the motions of the stars, in Europe, North Africa and the Middle East, amongst both eclectic philosophers and authors representing all the major faiths of their times.
In pre-Socratic philosophy, it became increasingly distinguished as a source of knowledge and reasoning opposed to mere sense perception or thinking influenced by the body such as emotion.
[14] For example, in his Memorabilia 1.4.8, he describes Socrates asking a friend sceptical of religion, "Are you, then, of the opinion that intelligence (nous) alone exists nowhere and that you by some good chance seized hold of it, while—as you think—those surpassingly large and infinitely numerous things [all the earth and water] are in such orderly condition through some senselessness?"
[18] In his Cratylus, Plato gives the etymology of Athena's name, the goddess of wisdom, from Atheonóa (Ἀθεονόα) meaning "god's (theos) mind (nous)".
In his Phaedo, Plato's teacher Socrates is made to say just before dying that his discovery of Anaxagoras' concept of a cosmic nous as the cause of the order of things, was an important turning point for him.
Just exactly how Plato believed that the nous of people lets them come to understand things in any way that improves upon sense perception and the kind of thinking which animals have, is a subject of long running discussion and debate.
On the other hand, in the Meno for example, Plato's Socrates explains the theory of anamnesis whereby people are born with ideas already in their soul, which they somehow remember from previous lives.
Concerning the cosmos, in the Timaeus, the title character also tells a "likely story" in which nous is responsible for the creative work of the demiurge or maker who brought rational order to our universe.
As mentioned above, Plato criticized Anaxagoras' materialism, or understanding that the intellect of nature only set the cosmos in motion, but is no longer seen as the cause of physical events.
Students of the history of philosophy continue to debate Aristotle's intent, particularly the question whether he considered the active intellect to be an aspect of the human soul or an entity existing independently of man.
[36] Alexander was also responsible for influencing the development of several more technical terms concerning the intellect, which became very influential amongst the great Islamic philosophers, Al-Farabi, Avicenna, and Averroes.
Together with his conjugate female Aeon, Aletheia (truth), he emanates from the Propator Bythos (Προπάτωρ Βυθος "Forefather Depths") and his co-eternal Ennoia (Ἔννοια "Thought") or Sigē (Σιγή "Silence"); and these four form the primordial Tetrad.
After her restoration, Nous, according to the providence of the Propator, produced another pair, Christ and the Holy Spirit, "in order to give fixity and steadfastness (εις πήξιν και στηριγμόν) to the Pleroma."
[48] A similar conception of Nous appears in the later teaching of the Basilideans, according to which he is the first begotten of the Unbegotten Father, and himself the parent of Logos, from whom emanate successively Phronesis, Sophia, and Dunamis.
But in this teaching, Nous is identified with Christ, is named Jesus, is sent to save those that believe, and returns to Him who sent him, after a Passion which is apparent only, Simon of Cyrene being substituted for him on the cross.
The identity of this list with the six material objects alleged by Herodotus[55] to be worshipped by the Persians, together with the supreme place given by Simon to Fire as the primordial power, leads us to look to Iran for the origin of these systems in one aspect.
The exact precedents of al-Farabi's influential philosophical scheme, in which nous (Arabic ʿaql) plays an important role, are no longer perfectly clear because of the great loss of texts in the Middle Ages which he would have had access to.
However while these three all placed the active intellect "at or near the top of the hierarchy of being", al-Farabi was clear in making it the lowest ranking in a series of distinct transcendental intelligences.
According to Davidson (p. 59):The lower of the two levels, labeled specifically as "prophecy" (nubuwwa), is enjoyed by men who have not yet perfected their intellect, whereas the higher, which Alfarabi sometimes specifically names "revelation" (w-ḥ-y), comes exclusively to those who stand at the stage of acquired intellect.This happens in the imagination (Arabic mutakhayyila; Greek phantasia), a faculty of the mind already described by Aristotle, which al-Farabi described as serving the rational part of the soul (Arabic ʿaql; Greek nous).
This faculty of imagination stores sense perceptions (maḥsūsāt), disassembles or recombines them, creates figurative or symbolic images (muḥākāt) of them which then appear in dreams, visualizes present and predicted events in a way different from conscious deliberation (rawiyya).
In the later model of the universe, which was transmitted to Christian philosophers, Averroes "dismisses emanationism and explains the generation of living beings in the sublunar world naturalistically, all in the name of a more genuine Aristotelianism.
Despite being widely considered heretical, the position was later defended by many more European philosophers including John of Jandun, who was the primary link bringing this doctrine from Paris to Bologna.
Notable "Catholic" (as opposed to Averroist) Aristotelians included Albertus Magnus and Thomas Aquinas, the founder of Thomism, which exists to this day in various forms.
The Latin motto "nihil in intellectu nisi prius fuerit in sensu" (nothing in the intellect without first being in the senses) has been described as the "guiding principle of empiricism" in the Oxford Dictionary of Philosophy.
These philosophers explain the intellect as something developed from experience of sensations, being interpreted by the brain in a physical way, and nothing else, which means that absolute knowledge is impossible.
He felt that lesser known Greek philosophers such as Democritus "who did not suppose a mind or reason in the frame of things", have been arrogantly dismissed because of Aristotelianism leading to a situation in his time wherein "the search of the physical causes hath been neglected, and passed in silence".
[87] Hume even questioned the distinctness or peculiarity of human understanding and reason, compared to other types of associative or imaginative thinking found in some other animals.
As in classical and medieval philosophy, Berkeley believed understanding had to be explained by divine intervention, and that all our ideas are put in our mind by God.