In the third book of Homer's Odyssey, the title character's son Telemachus travels from Ithaca to Pylos, which is on the southwestern coast of Greece. There, Telemachus meets with Nestor and various members of his family.
Nestor tells Telemachus about an argument that occurred between Agamemnon and Menelaus after the fall of Troy. In the course of his comments, Nestor claims that none of the other Greeks in the army could rival Odysseus in "counsel" (i.e., the ability to give advice or provide plans). Nestor also declares that Odysseus "was supreme in all known stratagems" (A.S. Kline translation). Nestor also adds that he and Odysseus
never spoke on opposite sides, in council or assembly, but with one mind advised the Argives, wisely and shrewdly, how to achieve success.
Thus, for Nestor, Odysseus' greatest assets are his abilities involve the powers of thought and speech. This contrasts with Achilles, who surpassed all other Greeks in physical ability.