Know thyself
"Know thyself" is a philosophical Delphic-maxim which was inscribed upon the Temple of Apollo in the ancient Greek precinct of Delphi. The best-known of the Delphic maxims, it has been quoted and analyzed by numerous authors throughout history, and has been applied in many ways. Although traditionally attributed to the Seven Sages of Greece, or to the god Apollo himself, the inscription likely had its origin in a popular proverb.
Ion of Chios makes the earliest explicit allusion to the maxim in a fragment dating to the 5th century BC, though the philosopher Heraclitus, active towards the end of the previous century, may also have made reference to the maxim in his works. The principal meaning of the phrase in its original application was "know your limits" – either in the sense of knowing the extent of one's abilities, knowing one's place in the world, or knowing oneself to be mortal. In the 4th century BC, however, the maxim was drastically reinterpreted by Plato, who understood it to mean, broadly speaking, "know your soul".
In later writings on the subject, one common theme was that one could acquire knowledge of the self by studying the universe, or knowledge of the universe by studying the self. This was often explained in terms of the microcosm–macrocosm analogy, the idea that a human being is structurally similar to the cosmos. Another theme, which can be traced back to the Platonic Alcibiades I, is that one can only know oneself by observing other people.
Christian, Jewish and Islamic authors found various scriptural equivalents for the maxim, allowing them to discuss the topic of self-knowledge without reference to the pagan inscription. By the time of the Protestant Reformation, Christian theologians generally understood the maxim to enjoin, firstly, knowledge of the soul's origin in God, and secondly, knowledge of the sinfulness of human nature. In secular writings of the period, several new meanings emerged; among them, that "know thyself" was a command to study the physical properties of the human body.
During the 19th and 20th centuries, the maxim acquired several new associations. It was frequently quoted in German philosophy and literature, by authors such as Kant, Hegel and Goethe; it was cited as an analogue of "tat tvam asi", one of the "Great Sayings" of Hinduism; and it took on an important role in the developing discipline of psychoanalysis, where it was interpreted as an injunction to understand the unconscious mind.
In 20th century, "Know thyself" is also a simplified form of the Chinese proverb 知彼知己，百戰不殆, which in turn is derivced from The Art of War Chapter III Attack by Stratagem.
Origin
According to ancient Greek and Roman authors, there were three maxims prominently inscribed upon the Temple of Apollo at Delphi: "know thyself", "nothing too much" and "give a pledge and trouble is at hand". Their exact location is uncertain; they are variously stated to have been on the wall of the pronaos, on a column, on a doorpost, on the temple front, or on the propylaea. The date of their inscription is also unknown, but they were present at least as early as the 5th century BC. Although the temple was destroyed and rebuilt several times over the years, the maxims appear to have persisted into the Roman era, at which time, according to Pliny the Elder, they were written in letters of gold.The three sayings were traditionally said to have originated with the Seven Sages, a legendary group of philosophers and statesmen who flourished in the 6th century BC. The first known reference to the Seven Sages is in Plato's Protagoras, where they are said to have collectively authored the first two maxims. The names of the sages are given by Plato as Thales, Pittacus, Bias, Solon, Cleobulus, Myson and Chilon; but in the works of later writers, some of these names are dropped and others added in their place. Each of the maxims was often attributed to a particular sage, and some authors, such as Demetrius of Phalerum, assigned additional sayings to the four remaining sages. There was no general agreement over which maxim belonged to which sage, but "know thyself" was most commonly attributed to Chilon.
Another popular theory held that the maxims were first spoken by the Delphic oracle, and therefore represented the wisdom of the god Apollo. Clearchus of Soli, among others, attempted to reconcile the two accounts by claiming that Chilon, enquiring of the oracle what was best to be learnt, received the answer "know thyself", and subsequently adopted the maxim as his own. In all likelihood, however, the sayings were simply common proverbs of much earlier date, which gained a new significance from their prominent position on the temple.
History of interpretation
Greco-Roman antiquity
Earliest references
Certain sayings of the philosopher Heraclitus, whose work survives only in fragments, may have been inspired by the Delphic maxims; if so, they represent the earliest known literary references. One of these fragments reads: "It belongs to all men to know themselves and think well ". According to classicist Charles H. Kahn, this fragment echoes a traditional belief that "know thyself" had an essentially similar meaning to the second Delphic maxim, "nothing too much"; both sayings might be considered alternative ways of describing the virtue of . In another fragment, Heraclitus defines as the art of "perceiving things according to their nature", apparently referring to the perception of objective, material facts. If so, and if self-knowledge is the same as, then, as Kahn writes, "the deepest structure of the self will be recognized as co-extensive with the universe in general … so true self-knowledge will coincide with knowledge of the cosmic order".Another fragment of Heraclitus which seems to allude to the maxim is B101: "I went in search of myself". The implication here, that to know oneself is difficult, appears to contradict the claim in B116 that self-knowledge is something that all men can or should accomplish. Kahn understands the lesson of the two fragments taken together to be that, while all men have the ability or capacity to know themselves, only a very few will arrive at that knowledge. Expanding on this, Christopher Moore argues that Heraclitus viewed self-knowledge as a continuous process rather than a destination, since the recognition of oneself as an epistemic agent brings with it the desire to improve one's ability to know. Ultimately, however, the meaning of these fragments cannot be established with any certainty.
A fragment from Ion of Chios provides the earliest explicit reference to the maxim. It reads: "This 'know yourself' is a saying not so big, but such a task Zeus alone of the gods understands." Again, it is not possible to infer from this what sort of task "knowing oneself" was understood to be, except that it was something extremely difficult to accomplish, but the fragment bears testimony to the fact that the phrase was a well-known saying during Ion's lifetime.
"Know your limits"
A clearer application of the maxim occurs in Prometheus Bound, a play attributed to Aeschylus and written sometime before 424 BC. In this play, the Titan Prometheus is chained to a rock as punishment for defying the gods. He is visited by Oceanus, who advises him: "Know yourself and adopt new habits, for there is even a new leader among the gods." In this context, "know yourself" may carry the meaning of "know your limitations" or "know your place"; indicating that Prometheus must accept that the new leader of the gods, Zeus, is more powerful than himself.Some scholars dispute this interpretation, but the use of "know yourself" to mean "know your limits" is demonstrated in other ancient texts. Xenophon's Hellenica, for example, describes the overthrow of the Thirty Tyrants by the citizens of Athens in 403 BC, after which Thrasybulus addresses the defeated tyrants as follows: "I advise you... men of the city, to know yourselves. And you would best learn to know yourselves were you to consider what grounds you have for arrogance, that you should undertake to rule over us." He then asks whether they think they are more just, or more courageous, or more intelligent than other men, indicating that to know oneself is to know one's worth in comparison to others.
In another work of Xenophon, the Cyropaedia, the Lydian king Croesus is captured in battle by Cyrus, and laments his failure to follow the advice of the oracle at Delphi, who had told him that he must know himself in order to be happy. In attempting to wage war against Cyrus, he had overestimated his own ability, and his defeat is therefore a just reward for his ignorance of himself.
Among Latin examples of this usage, the poet Juvenal wrote in his 11th Satire that men should not attempt to live beyond their means, and should be aware of their position in the social hierarchy:
Many other instances may be attested of the use of the maxim to mean "know your limits", and this appears to have been its principal meaning up until the 6th century AD. A related usage, possibly inspired by Stoic philosophy, takes the phrase as a memento mori, i.e. "know that you are mortal"; it is quoted with this application by authors including Menander, Seneca, Plutarch and Lucian.
Platonic references
The Greek philosopher Plato discusses the Delphic maxims, and particularly "know thyself", in several of his Socratic dialogues, and his writings on the subject had a major influence on later interpretations.In Charmides 164d–165a, Critias argues that self-knowledge is the same as sophrosyne. He claims that the purpose of the inscription at Delphi is to serve as Apollo's salutation to those who enter the temple – instead of "Hail!", he says "Be temperate!". Critias suggests that the other maxims were added later by those who mistook the first inscription for a piece of general advice rather than a greeting.
In the dialogue, Socrates casts doubt on the identification of self-knowledge with sophrosyne, but ultimately leaves the question unresolved. However, the work inspired later writers such as Porphyry, Philostratus and Olympiodorus to connect the maxim not only with temperance but also with the other cardinal virtues of courage, justice and wisdom.
In Phaedrus 229e–230a, Socrates is asked whether he believes in the literal truth of the Greek myths; he replies that the myths may have rational explanations behind them, but he himself has no time to investigate these questions:
This passage provides the first recorded use of the maxim in the sense of "knowing one's soul". Modern scholarship is divided as to whether Socrates is talking here about knowing one's own individual soul, or knowing more generally what it is to be human. His framing of the question in comparative terms seems to suggest that even if he only seeks to know himself as an individual, his character, as Charles L. Griswold writes, "will have to be understood relative to some larger context of which he is one part".
In Alcibiades I, Socrates persuades the youth Alcibiades not to enter into politics until he is further advanced in wisdom. Self-knowledge is one of the main themes of the dialogue, and Socrates quotes the Delphic maxim several times throughout.
On the first occasion, Socrates uses the maxim in its traditional sense of "know your limits", advising Alcibiades to measure his strengths against those of his opponents before pitting himself against them. Later, after convincing Alcibiades of the necessity of cultivating or taking care of himself, Socrates again makes reference to the maxim when he argues that one cannot cultivate oneself without first knowing what is meant by the word "self" – and to know this, as the Delphic inscription implies, is something "difficult, and not for everybody". In the ensuing dialogue, the two men agree that the self is not the body, and neither is it some combination of soul and body; they therefore conclude that a man's self is "nothing other than his soul".
Socrates then considers how one should obtain knowledge of the soul. He begins by asking how they would solve the puzzle if, instead of "know thyself", the inscription at Delphi had read "see thyself". He observes that the surface of an eye is reflective, and that an eye is therefore able to see itself by looking into another eye – specifically, into the pupil, that part of an eye "in which the good activity of an eye actually occurs". By analogy, for a soul to know itself, "it must look at a soul, and especially at that region in which what makes a soul good, wisdom, occurs". This region "resembles the divine, and someone who looked at that and grasped everything divine... would have the best grasp of himself as well". Commentators who focus on this latter point interpret Socrates' argument to mean that self-knowledge is accomplished through knowledge of God; while others, concentrating on the image of eye looking into eye, infer that self-knowledge is accomplished only through knowledge of other human souls.