The lasting contribution of the Greeks to the West is not only in their political philosophy, they are of course given credit for the creation of democracy, but with their philosophical tradition in itself, from which their politics emerge really. In other words, their political philosophy and modes of governing were closely tied to the more broad tradition of philosophy (literally “love of wisdom”) from which it emerges. This link is clearly seen in Plato’s Republic where the connection of philosophy, virtue and the ideal city state is outlined in detail and in his less well known treatise Laws, a work believed to have been written by Plato toward the end of his life which also addresses political philosophy and the role of law in society in particular. Aristotle’s work, most notably in Politics, also addresses political philosophical issues through the same link that Plato uses, notably in the exploration of the ideal man and the role of ethics and virtue in governance in general.
This tradition, this revolution really, of the supremacy of Reason and Logic over myth and tradition is what marks the Greek philosophical tradition more so than any other characteristic, and it is this tradition that marks their lasting contribution to Western civilization. And underlying this tradition is that it is the Mind, mankind as a thinking being, which distinguishes it from the rest of the creatures that roam the Earth.
While neither the works of Aristotle or Plato address or analyze the mental faculty directly in their works, the role of Mind, characterized most notably by Reason and the ability to deduce or induce facts that stand up to the test of intellectual coherence and consistency, i.e. cannot be refuted or at least are difficult to be refuted, is the common theme to really all of their work. And it is this thinking faculty that is called out as the distinguishing and special characteristic of man. Aristotle not surprisingly is the first to outline explicitly these faculties of man, and thinking in particular, within the context of his exploration of the Soul, or that which animates living things, in his work entitled On the Soul (De Anime in Latin).
But before we look at the view of Plato and Aristotle on the Mind and the thinking faculty and how they influenced Western thought down through the millennia that followed, it is important to draw attention to the work of Anaxagoras, a pre-Socratic philosopher who is best known for putting forth the role of Mind, in the cosmic capacity perhaps best described as the collective and ethereal Mind, at the forefront of not only his cosmological worldview, I.e. how and by what means the universe has come into existence, but also in his metaphysics as the primary principle which governs and balances the physical universe, a principle which sits outside of and independent of any of the basic elements which make up the universe itself. Even though Plato and Aristotle reject the metaphysics of Anaxagoras, it clearly influences their philosophy, if only to serve as a counterpoint to their theories of Mind, and in turn Soul to which the thinking faculty of man is closely related.
According to Diogenes Laertius, Anaxagoras acquired the nickname Mr. Mind (DK 59 A1); his view that the cosmos is controlled by nous, mind or intelligence, first attracted and then disappointed Socrates (Plato, Phaedo 97b8ff.). Plato and Aristotle applauded Anaxagoras for using nous as the first principle of motion, but both criticized him for failing to be consistent in that use, arguing that once he invoked Mind to set the original mixture in motion, Anaxagoras reduced later causes to mindless mechanism.
Before we delve into the role of the intellect, or mind within the context of Platonic doctrine and extant works, or even the Corpus Aristotelicum it is important to (re) visit the close correlation between what today we might call the “cognitive faculty” of man, perhaps best viewed as the derivation of Descartes’s cogito ergo sum, and what the ancients looked at as the notion of Soul. The concepts are very closely related, particularly in the Platonic and Aristotelian traditions, and in fact it is through their philosophical developments in particular that the cognitive faculty of man, thinking and discernment we might call it, start to evolve as separate and distinct qualities that are somewhat independent of the notion of Soul itself.
We can perhaps best see this when we look at the word psychology itself and how it has come to be synonymous with the study of mind in modern day nomenclature and usage. The root part of the word however, “psyche”, comes from the Greek word for soul “psyche” or “psuche”. From the online etymology dictionary we have the following etymological description for the term ‘psychology”:
1650s, “study of the soul,” from Modern Latin psychologia, probably coined mid-16c. in Germany by Melanchthon from Latinized form of Greek psykhe- “breath, spirit, soul” (see psyche) + logia “study of” (see -logy). Meaning “study of the mind” first recorded 1748, from Christian Wolff’s “Psychologia empirica” (1732); main modern behavioral sense is from early 1890s.
So we can see clearly this close connection between the study of mind, study of the human intellect, and the notion of the human soul, and this correlation, this connection goes back to the Greek philosophical tradition, speaking to the profound influence that this tradition has had on Western thought even some 2500 years after its inception. Today we clearly view psychology as the study of the human psyche, but we forget the etymology and derivation of the term from our ancient Greek ancestors.
Keeping this in mind then (no pun intended), when we look for how Platonic and then in turn Aristotelian doctrine and philosophy framed this notion of mind, the thinking faculty of man, we must look at their conceptions of the Soul, and to what extent they viewed this thinking faculty of man, mind in the individual sense, as independent of the soul. And in so doing, what we find is that the notion of the soul itself undergoes transformation and evolution in the Ancient Greek world, as first put forth and reflected in the works of Homer, and then in the Pre-Socratic philosophical tradition (Heraclitus, Anaxagoras who has already been mentioned, Pythagoras, etc.), then in the philosophy of Plato and then in the philosophy of Aristotle.
The unique characteristic of Plato’s writings is, as has been well documented and explored by scholars throughout the ages, is his style, the format within which he explores and presents his ideas – namely through dialogue and what has come to be known as dialectic. From the Wikipedia entry on dialectic we are presented with the following definition:
Dialectic (also dialectics and the dialectical method) is a method of argument for resolving disagreement that has been central to European and Indian philosophy since antiquity. The word dialectic originated in ancient Greece, and was made popular by Plato in theSocratic dialogues. The dialectical method is discourse between two or more people holding different points of view about a subject, who wish to establish the truth of the matter guided by reasoned arguments.
The method itself, the modus operandi through which Plato presents his teachings, had lasting effects on the development of Western thought, and teaching of philosophy in general, that lasted well throughout the middle ages, continuing to be used as the means of teaching to a greater or lesser extent as it evolved into its more modern form which came to be known as scholasticism which was used as the teaching methodology for many of the earliest universities that cropped from the 11th century onwards up through the Enlightenment era.
The format that Plato uses throughout all of his works is one of the presentation of differing points of view of an argument by various characters in his dialogues in order to explore, and ultimately conclude, various philosophical points. The common thread throughout these dialogues is the supremacy of Reason, the use of logic and argument, to establish various points of view as well as basic philosophical and metaphysical positions, upon which what we know today as Platonic philosophy is presented to the modern reader.
It is commonly assumed that the doctrines and philosophical positions that Plato lays forth in his dialogues represent his philosophical position more or less, and many of the characters and (alternative) points of view and positions that are explored in his dialogues represent to some degree more or less some of the varying philosophical positions that were presented and common place in the philosophical community and era within which Plato writes – for example the views of Anaxagoras, Parmenides, etc who are all presented as characters in his dialogues that to at least some degree represent the positions of the various competing philosophical schools that Plato is attempting to refute. Furthermore, in almost all cases Plato’s views and positions are presented through the voice of Socrates, who remains a consistent and esteemed character in virtually all of Plato’s dialogues through which Plato’s philosophical positions, and his arguments to back up these positions, are argued from.
There remains some question of course, and Charlie found surprisingly little debate among scholars around this point, as to whether or not Plato is presenting his own views through the voice of Socrates in his dialogues, or if he is in fact regurgitating Socrates’s teachings through his own voice. It is safe to presume that is some combination of the two, or perhaps better put, the voice of Socrates in Plato’s dialogues represents Plato’s interpretation of the philosophy of Socrates that he learned and understood from him as his disciple, which there is no doubt that he was.
Plato’s works are typically referred to as the Socratic Dialogues, not only due to the fact that Socrates is a prominent character and voice of the philosophical tenets which Plato’s puts forth, but also alluding to the fact that the assumption is typically made that the philosophical principals that Plato establishes in his dialogues are assumed to be the documentation and transcription of the philosophical principals which he learned from Socrates himself. But outside of second hand accounts, we have no direct works from Socrates so for the most part we know of Socrates and his philosophical beliefs and metaphysics through the words of Plato.
These are important backdrop and contextual items that must be kept in mind when looking at Plato’s works and discerning what his “philosophy” truly was, and how much of it was his interpretation of Socrates and how much of it was his own workings and reformulations of the teachings which he presumably received from Socrates himself. We see for example that Aristotle, who studied at Plato’s Academy and presumably was a disciple or at the very least a very close student of Plato’s, differs from Plato on several key, metaphysical points and principles and it’s not until we see Aristotle’s work, and the school of philosophy which he founded (the Peripatetic school) where we find a much more thorough and complete (and certainly what Aristotle would deem more coherent) philosophical system that although shares many common characteristics and principles of his predecessor, differs from him on several key points – differences that were the subject of debate of subsequent scholars for centuries to follow (millennia in fact).
But again, when trying to discern or determine “Plato’s philosophy”, or Platonism in its early stages as it is sometimes referred to, it is important to remember that perhaps Plato’s most lasting contribution to Western thought was not necessarily the philosophy that he presented, the one which he assume he learned from Socrates, but the means by which he presented and explored these philosophical principles – through dialogue and debate, i.e. dialectic – a method which was much more profound and lasting in and of itself than the doctrines and belief systems that we infer to be contained or found in Plato’s works and a method which rested on the supremacy of Reason, and argument and logic to a great extent, over myth or blind faith. A constant theme in all of Plato’s dialogues then is the method of teaching itself, a method which spoke to the power of the mental faculty of man moreso than any of his predecessors, predecessors which had for the most part relied on poetry and mythology as tools of exposition and explanation (and to some extent even mysticism in the sense of direct “divine revelation” and the absence of reason or logic from which poetry can be seen to have derived) and the establishment of truth.
It also relevant of course that this method of teaching, the philosophical system of “learning” that Plato is classically given credit for founding, led to the formulation of the first true academic center of learning itself, namely the Academy in Athens which Plato founded circa 387 BCE and persisted for some three centuries after his death, Aristotle of course having studied there for some twenty years before moving on and starting his own school the Lyceum.
In light of these facts, when we look for Plato’s theory of mind, or at least how he perceived and viewed the mental faculty through which the physical world was perceived, we must look at his body of work as a whole and discern from it what his principles and beliefs and philosophical tenets were with respect to not only the mind and cognitive faculty specifically but also his notion of the Soul which was very closely correlated to the notion of mind from his perspective.
Whereas Aristotle laid out a system of metaphysics and set of teachings that were broadly categorized by topic and were for the most part at least logically organized (with some overlap of course), in studying Plato and discerning his, or by extension perhaps Socrates’s, philosophical positions we must look at his body of work in toto. And like any philosopher, or like any individual for that matter, his views matured over time and adjusted and evolved somewhat, which is why historians have divided Plato’s works into what they believe are the order, the timing, which they were written – his Early Dialogues, his Middle Dialogues and then his Late Dialogues which are considered the most dense and sophisticated of his works. These categories are not concrete and definitive of course, and are open to a great deal of scholarly debate, but for the most part it is a generally accepted division of Plato’s work where we can at least have the opportunity to view the evolution of his views and philosophical principles over time. It is from the Middle Period that we find his exploration of the notion of Soul, first in Phaedo which delves into the nature of the Soul and whether or not it persist beyond the death of the body, a work almost solely devoted to this topic, and then in his famous Republic which deals with the notion of Justice, which in turn is looked upon as the perfect state of the Soul, within which the role of Reason is called out specifically as an attribute of the Soul and a more thorough treatment of the Soul and its parts is given relative to the work on the Soul in Phaedo.
Plato’s greatest contribution to Western philosophy is no doubt his Theory of Forms, which in essence breaks down existence itself as not only a physical world of inanimate and animate objects, but a theory of knowledge and understanding which is based upon the notion that a) the understanding of a thing is predicated upon the existence of a true Form, or Idea of a thing without which the understanding, or even the thing itself, could not truly “exist”, and b) that such Forms or Ideas existed eternally as intellectual constructs upon which our understanding of the world around us is based. It is from this premise and starting point that we must begin to try and grasp Plato’s perspective on the role of the human mind, the act of perception, and ultimately his views on the Soul which are very much inextricably linked to his views on the mind and the means by which we can truly understand or comprehend anything.
In this context we must view his argument of the immortality of the Soul in Phaedo, which hinges off of the immortal and undying existence of intelligibles, upon which the Soul consists of and is characterized by. His notion of intelligibles is contrasted with his view of particulars, which could be best described as specific characteristics and qualities of things, of substances, which have some existence in physical reality. These particulars exist as extensions of, characteristics again, of those things which have an existence in time and space, which are perishable in fact. The Soul however deals in and exists in the contemplation of imperishable Ideas and Forms, these intelligibles which exist beyond time and space and do not indeed perish. It is with this intellectual and metaphysical dualistic type of reality that Plato establishes his argument for the immortality of the Soul – for how can Soul which is so closely correlated and associated with intelligibles which in and of themselves are not perishable, perish in and of itself at death? This is the essence of what is sometimes called Plato’s affinity argument, so called because it establishes the Soul’s affinity of and to the imperishable world of intelligibles and therefore must and should share the same characteristics of this imperishable phenomena, i.e. is imperishable and immortality, in and of itself.
What is implied in this description of, and argument around the nature of the soul of course is the idea that, the implicit belief, that the Soul is a thinking thing, or perhaps better articulated that the Soul is that which contemplates intelligibles, or more specifically that which contemplates Ideas or Forms. Although Plato doesn’t directly call out the connection between his Forms and intelligibles in Pheado it is not that big of a leap to derive the connection, for his Theory of Forms is articulated and laid out most clearly in the Allegory of the Cave in the Republic, which is in all likelihood and later more mature work of Plato’s.
What is also presumed in this argument in Phaedo is of course that it is the Soul which gives life to the body, a presumption that permeates the work (and virtually all of Greek philosophical doctrine before and after Plato in fact). This is perhaps best illustrated by the notion that the idea of “being alive” in classical Greek is typically and broadly described by the word ensouled, or “empsuchos”. And the Soul, throughout Homer’s work as well in the Pre-Socratic philosophers straight through Plato’s and Aristotle’s work, is not only presumed to be that principle which gives life to animate things, but also that which is the source of a variety of basic moral and ethical constructs which characterize the human condition, namely courage, valor and other human characteristics that are aspired to in the not only the Homeric tradition, but then as we see in Plato’s Republic, the notion of Justice as well.
In the Republic, perhaps the greatest if not one of the greatest works attributed to Plato, his intention is to lay out and describe the notion of Justice, and how that in turn is related to the individual, happiness in general, and the implications for the ideal state of governance, a topic that was of great importance to the ancient peoples of the Mediterranean at the time period when this philosophic revolution takes place, being that the majority of Plato’s young life was marked by extreme political strife and war, namely the Peloponnesian conflict which pitted two very different forms of government against each other, i.e. the tyranny of Sparta against the democracy of Athens.
In the Republic, or On Justice, Plato is forced to come up with a somewhat more coherent view of the Soul relative to what we find in Phaedo, to describe its facets in a more detailed and thorough way than he does in Phaedo, primarily because he is not simply (not that there is anything simple about it) dealing with the establishment or discussion of the immortality and imperishable nature of Soul, but dealing with the idea of whether or not there is an ideal state of the Soul that individuals should aspire to, a concept which Plato attaches to and feeds into his concept of Justice, which he perceives to be or even defines as, the ideal state of the Soul, from which the ideal state itself ultimately derives.
In this conception of the Soul, which is thread and alluded to throughout the Republic, particularly in Book 1, Book 4 and then less directly in Books 8 and 9 which deal with the corrupt forms of state and soul, Plato outlines not only the Soul’s basis in giving life, animating the body, but also its role in establishing order, or reason (logos) in the life of the individual, as well as being the source of what he refers to as spirit (loosely defined as the guiding force of individuals to seek honor and respect by their peers and is naturally aligned to reason to a great extent), and appetite which is described as the desire for food, drink and sex. In toto then what we find in the Republic is a coherent view of the Soul as the source of the basic driving needs of man, the alignment or proper direction of which leads to the living of a just, and in turn a happy, life, from which collective justice and collective happiness of the state can be derived or found. The proper functioning and use of the deliberative and rational faculties of man is called out as the source, the pillar, from which the just man, the happy man, is derived:
Then next consider this. The soul, has it a work which you couldn’t accomplish with anything else in the world, as for example, management, rule, deliberation, and the like, is there anything else than soul to which you could rightly assign these and say that they were its peculiar work?” “Nothing else.” “And again life? Shall we say that too is the function of the soul?” “Most certainly,” he said. “And do we not also say that there is an excellence virtue of the soul?
Perhaps the most definitive and mature view of Plato’s Soul, and the explicit relationship to God (or gods, “theos” as the case may be), is provided to us in Laws, what is viewed as his last and perhaps greatest work. In Laws, Plato explores the nature and origin of law within the state, in many respects covering ground that has already been covered in the Republic, but with perhaps a more cynical, or realistic point of view, reflecting perhaps his perspective on the ideal state toward the tail end of his life after coming to grips with the limits of philosophy within the sphere of power, i.e. politics. It can be looked at as perhaps a more practical treatise on political philosophy where the ideal state of the individual, i.e. Justice, and its attainment and relationship to the ideal state is somewhat abandoned in lieu of the role, and source, of law that is required to govern a state’s citizens that perhaps are incapable of, or are ultimately flawed, in their pursuit of Justice and virtue.
As the nature and origin of laws are explored in Laws, the question of imposing piety toward God (or again “gods”, “theos” as the case may be) is brought up and therefore the discussion as to whether or not the God/gods can be said to exist is naturally covered. Leaving aside the question of whether or not Plato’s view of God in Laws specifically (which arguably records the penultimate views of Plato toward the end of his life) is monotheistic or polytheistic in nature – the latter of course being he more likely interpretation even though it is not alluded to specifically – Plato does appear to take a firm stance in theism proper, i.e. the belief that the Gods do in fact exist. His argument is at it turns out one based upon the existence of the Soul, the Soul being defined again as the source of movement of the body, or of a body, for he abstracts the notion of the human Soul to astral elements as well, moving up the chain to argue that if we indeed believe in the individual, human Soul, and in its nature as the source of movement, of life and order, for the individual, then we must in turn believe that the stars, the planets, the universe itself also has a Soul with the every same attributes. Good and evil are aligned, as they are in the Republic within the context of the discussion of Justice, with the proper balance and well functioning of the Soul – the important connection being made between good, balance, order, and reason, hence establishing perhaps Plato’s greatest contribution to the West, the clear distinction of reason and order above all else as the primary agents of human society and civilization.
Yes, very true; the soul then directs all things in heaven, and earth, and sea by her movements, and these are described by the terms-will, consideration, attention, deliberation, opinion true and false, joy and sorrow, confidence, fear, hatred, love, and other primary motions akin to these; which again receive the secondary motions of corporeal substances, and guide all things to growth and decay, to composition and decomposition, and to the qualities which accompany them, such as heat and cold, heaviness and lightness, hardness and softness, blackness and whiteness, bitterness and sweetness, and all those other qualities which the soul uses, herself a goddess, when truly receiving the divine mind she disciplines all things rightly to their happiness; but when she is the companion of folly, she does the very contrary of all this. Shall we assume so much, or do we still entertain doubts?
 For a very detailed overview of the Ancient Greek conception of the Soul throughout the Homeric and Pre-Socratic period as well as in the works of Plato and Aristotle, see Ancient Theories of the Soul by Hendrik Lorenz, published in the 2009 edition of the Stanford Encyclopedia of Philosophy, which can be found here: http://plato.stanford.edu/entries/ancient-soul/.
 Plato was present at Socrates’s final hearings of judgment, as we find in the Apology, which is Plato’s account of the Socrates’s defense which he lays out to his Athenian council members where he stands accused of “corrupting the youth and of not believing in the gods of the Athenian state”, a crime punishable by death apparently to which Socrates willingly accepts. His reasoning for the acceptance of this judgment is related in the Crito which is an account of a conversation between Socrates and Crito while Socrates awaits his death sentence in his cell which covers the topics of justice and injustice among other things.
 Plato’s Phaedo and Republic were alternatively referred to in antiquity as On the Soul and On Justice respectively, speaking to the prominence of these two themes in the works themselves.
 For a more detailed look at this “affinity argument”, see Ancient Theories of the Soul by Hendrik Lorenz, published in the 2009 edition of the Stanford Encyclopedia of Philosophy, pgs. 10-14 which can be found here: http://plato.stanford.edu/entries/ancient-soul/.
 Plato Laws, X. Translation by Benjamin Jowett. From http://www.sacred-texts.com/cla/plato/laws/laws09.htm.