The discovery of philosophy in ancient Greece was spurred on by a “marketplace of ideas” where rational justification trumped doctrinal authority.

Every culture has a philosophy, if all one means by “philosophy” is an overall worldview defining the nature of reality, of human beings, and of the proper standards of individual and social conduct. But if we take “philosophy” in the strict sense of an intellectual discipline that attempts to formulate such a worldview through reasoned arguments, without appeal to tradition or authority, then philosophy appears to have independently arisen only three times in human history: in India, China, and Greece, all around the 7th-6th centuries BCE. 1

While economic, political, social, and cultural preconditions for the emergence of philosophy are doubtless many, one important factor seems to be that of intellectual competition. Where the proponents of a given worldview are able to maintain a monopoly, they do not need to defend their doctrines via argument; critics can be silenced, or do not think to become critics in the first place. But in cases where it is impractical to impose a single viewpoint by authoritative fiat, those who want their opinions accepted must offer reasons; hence there may arise a motivation for argumentation and debate. Likewise, those who seek the truth can no longer simply go to the tribal elders for answers, because there is no single set of tribal elders to appeal to; faced with competing claims to wisdom, the inquirer must look for evidence favoring one set of claims over another. Thus philosophy can be seen as an offspring of Hesiod’s good Strife.

Intellectual competition appears to have played a role in the emergence of philosophy in all three traditions, but in different ways. In India, a practice of discussion and debate seems to have taken shape in the competition for spiritual authority between the brahmin and kshatriya classes – in effect, between church and state. In China, rivalry among the “Hundred Schools” arose through displaced bureaucrats and political functionaries vying for the post of political advisor to the local princes and military chiefs who were carving newly independent kingdoms out of the fading remnants of the Zhou Dynasty.

In the case of Greece, the competition appears to have had a multicultural component. In an age when travel by sea was easier and safer than travel by land, the eastern Mediterranean, with its thousands of islands (many landmarks for navigators) and calm waters (by comparison with the open ocean, at least) was ideal for trading voyages. Such commerce – both among Greek communities, and with foreign nations in Egypt, Italy, and the Persian Empire – promoted exchange of ideas as well as of goods. Philosopher of science Karl Popper describes the “rise of Greek poetry, art, philosophy, and science,” and thus the “origin of Western rationalism,” as “largely due to culture clash.” As Popper points, philosophy arose on the periphery of the wider Greek world rather than in mainland Greece itself:

Let us look for a moment at the origin of Greek philosophy and Greek science. It all began in the Greek colonies in Asia Minor, in Southern Italy, and in Sicily. These are places where the Greek colonists were confronted with the great civilizations of the East, and clashed with them, or where, in the West, they met Sicilians, Carthaginians, and Italians .…2

It’s harder to be confident that the moon is a goddess, for example, when your Egyptian trading partners are just as confident that the moon is a male god. Hence confrontation with alien cultures sparks the need to figure out the truth rather than simply taking for granted the traditions of one’s culture. The influx of wealth generated by trade also tended to undermine the authority of the traditional aristocracy, as economic power in many cities shifted to the middle class.

Competition within Greece probably played a role as well. The Greek world, like its counterparts in India and China, was politically decentralized. Moreover, Greek religion had no sacred scripture, and as a religion focused more on practice than on doctrine it likewise had no official list of unchallengeable dogmas. 3 To be sure, there were limits to the toleration of religious eclecticism; Anaxagoras, for example, got into legal trouble for claiming that the sun was a burning rock rather than a god. But there was no pagan Greek equivalent of the medieval Christian insistence on conformity to detailed doctrinal minutiæ over the precise nature of the Trinity or the Incarnation; thus the range of permissible dissent and diversity was significantly greater.

The claim that Greek philosophy arose in part through multicultural contact should not be confused with the claim that the Greeks found the discipline of philosophy already extant in some other culture and simply appropriated (or “stole”) it for themselves. 4 Those who point in particular to Egypt as the “true source” of Greek philosophy have plausibly identified some similarities in doctrine that suggest likely influence; but the Greek texts differ from the Egyptian ones in ordinarily containing arguments for their doctrines, whereas the equivalent doctrines in the Egyptian texts are merely asserted, not defended. Doctrines without arguments, though they may serve as the raw material for philosophical reflection, are not themselves philosophy.

The classical Greeks were fascinated by cultural differences. The historian Herodotus recounts one famous example, in ethics:

Dareios in the course of his reign summoned those of the Hellenes who were present in his land, and asked them for what price they would consent to eat up their fathers when they died; and they answered that for no price would they do so. After this Dareios summoned those Indians who are called Callatians, who eat their parents, and asked them in presence of the Hellenes, who understood what they said by help of an interpreter, for what payment they would consent to consume with fire the bodies of their fathers when they died; and they cried out aloud and bade him keep silence from such words. … For if one should propose to all men a choice, bidding them select the best customs from all the customs that there are, each race of men, after examining them all, would select those of his own people; thus all think that their own customs are by far the best .…5

And the philosopher Xenophanes describes another example, in theology:

Ethiopians say that their gods are snub‐​nosed and black;
Thracians that theirs are blue‐​eyed and red‐​haired. …
But if horses or oxen or lions had hands
or could draw with their hands and accomplish such works as men,
horses would draw the figures of the gods as similar to horses, and the oxen as similar to oxen,
and they would make the bodies
of the sort which each of them had.6

But contrary to both Herodotus’s prediction and his own, in choosing among theological opinions Xenophanes does not “select those of his own people,” nor does he assign to the gods “bodies of the sort” possessed by Greeks or even humans. Instead, Xenophanes rejects the anthropomorphic polytheism of Greek mythology in favor of a single, incorporeal, changeless, spherical, all‐​knowing, morally perfect deity, on the grounds that such a conception is worthier of godhood than are the traditional stories. In short, Xenophanes responds to the phenomenon of religious diversity by looking for the most rationally defensible conception of deity, even if it departs sharply from what all known authorities teach.

The philosophoi were “lovers of wisdom” in the sense of being seekers after wisdom, or more precisely, seekers after standards whereby to distinguish genuine from fake wisdom. In its refusal to bow unquestioningly to authority, Greek philosophy was decidedly libertarian not only in its origin but in its method – if not always in its content.

1. And given that India lies geographically between China and Greece, and its philosophical tradition appears to be slightly earlier than those of the other two, the possibility of Indian influence upon the origins of Chinese and Greek philosophy cannot be ruled out. There’s no definite evidence in favor of such influence either, however.

2. Karl R. Popper, The Myth of the Framework: In Defence of Science and Rationality (Routledge, 2014), p. 38.

3. These features of Greek religion are paralleled in Indian and Chinese religion also. India did have a sacred scripture in the Vedas, but these are devoted more to instructions about practice than to doctrines – which is how the atheistic philosophers of the Purva‐​Mimamsa school were able to make a successful claim to the status of Hindu orthodoxy.

4. See, e.g., George G. M. James, Stolen Legacy: The Greeks Were Not the Authors of Greek Philosophy, But the People of North Africa, Commonly Called the Egyptians (New York Philosophical Library, 1954), and Martin Bernal, Black Athena: The Afroasiatic Roots of Classical Civilization (Rutgers University Press, 1987); for critique, see Mary Lefkowitz, Not Out Of Africa: How “Afrocentrism” Became an Excuse to Teach Myth As History (Basic Books, 1996), and Mary R. Lefkowitz and Guy MacLean Rogers, eds., Black Athena Revisited (University of North Carolina Press, 1996).

In my judgment, “Afrocentrist” scholars like James and Bernal are too quick to read vague similarities as specific ones, specific similarities as evidence of influence, and evidence of influence as evidence of “theft” (though Bernal is far more nuanced than James in these respects). On the other hand, critics of Afrocentrism such as Lefkowitz can be too quick to downplay evidence of influence. I think we have good grounds for thinking that the Greek philosophers picked up a number of ideas from Egypt – fewer than the Afrocentrists imagine, but more than the critics of Afrocentrism tend to acknowledge. I see no evidence, however, that the Egyptians had developed the philosophical method.

5. Herodotus, Histories III.38 , George Campbell Macaulay translation.

6. Xenophanes, Fragments 15–16: James H. Lesher, trans., Xenophanes of Colophon: Fragments: A Text and Translation With a Commentary (University of Toronto Press, 2001), pp. 89–90.