The Odyssey, one of the two major homeric epics (dated by scholars around the VIIIth century and possibly the oldest extant pieces of literature from the Greek world) , describes the adventures of Odysseus (Ὀδυσσεύς) -- Ulysses -- an Achean king from the island of Ithaca, on his way home. He is in both texts present and represents the epitome of cunning intelligence (μῆτις) -- Do note that this differs from "wisdom" as we mean it (more on that later).

In the Iliad one of his most memorable appearances is in song IX when he goes on an embassy to Achilles on behalf of the other Achean kings, to soothe his anger and convince him to come back to reason and war against Troy. He demonstrates in that song how closely related were for the Greeks intelligence and oratory skill. The text puts also in parallel the cunning intelligence of Ulysses (qualified of πολυμήτις, astute, of many experience) and the strength and other more blunt qualities of the impetuous Achilles (famously called "podas ochus", with fast feet -- it is a Greek grammar example). He is also contrasted with Ajax (also a strong and valiant Achean hero, not remembered for being smart, shall we say).

In the Odyssey, which describes his way back home from Troy we are given other examples of his quick, smart thinking : an example would be the way he defeats Polypheme the cyclops telling him he is "no one" so he can't be a victim of the monster's revenge and had his crew hide grabbing under sheep, so the blinded cyclops cannot find them by touching the sheep. Once again the contrast between the strong and, let's admit it, quite moronic cyclops and Ulysses puts in strong emphasis his genial qualities. Another example (in the oratory skills and flattery category) is when he awakes after a shipwreck on the beach where Nausicaa is washing her linen with her maidens and quickly hides his nakedness with a branch (kata khroi : regarding [parts] of his skin) and despite his pitiful appearance pulls out a very good speech (VI,149) convincing Nausicaa to bring him back to the palace and help him (Γουνοῦμαί σε, ἄνασσα· θεός νύ τις, ἦ βροτός ἐσσι; : I kneel before thee o queen, for I do not if you are a goddess or a mortal -- this is a very good way to introduce oneself to a lady apparently).

The moral ambiguity of Ulysses's intelligence was also described in ancient authors. Virgile in the Aeneid always depicts Ulysses as dirus (cruel) or various expressions suggesting he is some sort of a mischievous character. He not only does it as someone speaking from the Trojan point of view, but also as the author of a Roman patriotic work where Aeneas is supposed to exemplify both the prudent, "fatherly" intelligence combined with Roman civic and moral virtues someone like Ulysses could have been found lacking (honestas, dignitas, etc.) ; in that regard criticizing Ulysses is early principate propaganda.

The nature of the μῆτις of Ulysses was the topic of considerable scholarly discussion as it exemplifies a type of intelligence for which the French language has no perfectly suitable translation. M. Detienne and J.-P. Vernant, in Les Ruses de l’intelligence, la Mètis des grecs (their 1974 magnum opus) define it as deft, witty prudence based on deliberating in order to obtain a good (fondée sur la délibération en vue d'un bien). It is the practical application of logos, the deliberating thought so beloved by the Greeks. As they explain, emphasis on this peculiar brand of intelligence is characteristic of the Greeks as it combines a deliberating train of thought with the idea of achieving success over strength and contrary odds by the sudden breakthrough of a genial idea (i.e. the moment dialectique). It is also very different from ἐπιστήμη, the "pure knowledge" as it has a very practical, skillful component. As such, μῆτις appears when ἐπιστήμη and praxis come together in a cunning turn of thought allowing to overcome adversity, and when reason is able to join together various aspects of practical knowledge (praxis).

It was as such much admired by the ancient Greeks, and a quality well identified as early as the VIIIth century (estimated date of composition of the homeric epics in their relatively achieved form; possibly older if we retain the theories on the idea that they were assembled based on oral transmission). To call it a virtue would go a bit far nonetheless as it carried no moral component (in the modern sense) whatsoever (Ulysses is in this for his personal interest, but does not serve any greater moral purpose or values).

Separate from the Ancients — the notion of intelligence imparted by "genius" is a very specific one, one that we typically date to the Enlightenment in Europe (18th century or so, though there are some rare examples of it being used this way as early as the 16th century). The word "genius" refers to a "spirit" (and that is what its Latin origins refer to), and it was used to indicate divinely-inspired inspiration. So a "genius" was someone who God had inspired to do something amazing and literally awe-inspiring — think Michelangelo and the Sistine Chapel, Leonardo and the Mona Lisa, etc. It's an interesting word, in that it is a model of intelligence that is strictly speaking somewhat supernatural, and attributing the ultimate credit to a creation to something non-human.

Today of course we tend not to attribute anything human to the supernatural, though we still treat "genius" with a special awe, implying it is something a bit beyond human. It is interesting to contrast this approach to human mental or creative activity to other models, such as wisdom, which is not quite the same thing (wisdom is often imparted by experience; genius is typically seen as innate).