Dialegesthai as critical thinking
 There was a time when social, political and
natural changes were all taken under the same concept of physis,
word by which the ancient Greek meant both either what we call nature,
either the sphere of human life.
Later, as the believe that man and nature formed a whole appeared untenable and began to fade away, it was not world, but logoi the unsteady and changeable "places" where we apprehend the world, communicate and agree each other or are in conflict with each other- to draw attention and come strongly into the foreground.
It is in this new context that the term dialégesthai emerges as one of the mainstays of Philosophy.
A first occurrence of it can be found in Homers Iliad. In the XXII book, where the fight between Hector and Achilles and the death of the Trojan hero are told, there are verses in which Hector is caught in a dramatic moment of hesitation, striving with himself whether he had to take refuge inside the walls or face the fury of his Greek enemy. Homer describes the contending of such different ideas within Hectors heart - a "dispute" which involves what really matters, since life is here at stake and writes: dieléxato (v. 122), a verbal form coming from dialégesthai.
But it is in Socrates and Platos Athens that the verb assumes a primary position. Ouk erizein alla dialegesthai, Plato will say (Resp 454) distinguishing erizein, in which disputing was meant to be as a kind of fight, whose sole scope was to prevail and defeat the opponent, from dialegesthai, which, on the contrary, presupposes a quite different moral and logical attitude - above all, it presupposes a critical attitude, as Meno shows..
 To young Meno, in the Dialogue
having the same name, it seems quite obvious that to answer the
Socrates' question: what is virtue (arete) ?,
all he has to do is to focus on the different ways Greeks usually
employ the word, taking them as data, and then to draw up
a list: the virtue which is appropriate to men is excelling in
public life; the virtue which is appropriate to women is to look
after the housework; the virtue appropriate to children etc.
Against Meno's list, Socrates' objection is, at first, a technical one: to enumerate is not to give a definition and grasp "what is the same in all cases" (called ousia, at 72b, eidos, at 72c,d,e, dia panton estin, at 74a). But when we consider that e.g. the idea that the virtue can't be different for men and women is a genuine Socratic thesis (see Burnet, Socrates, in Encyclopaedia of Religion and Ethics, XI, p. 667) and that it is on this base that the participation of women in public life is justified in Respublica, V, then the general implications of the discourse will come into prominence. They concern what a community can take for granted and how to relate to it in philosophizing.
Taking up what Greeks usually say about the matter, without any further reflection, Meno assumes but commonplaces and fix them as they were standpoints of intellectual research.
The pair "surface", where Meno is bound to stay, and "depth", where his mistake excludes he can arrive at, could now tempt us and lead us to imagine a realm of eternal truths existing beyond our experience or, in Plato's words, beyond the sky. But the "depth" dialegesthai reveals is, anyway, always to be sought in the same place where a polis is and men live, under the sky, and, here in Meno, it seems to lay but in the interplay of our doxai, in the reciprocal linkings of everyday words we make use of.
 Since the word dialectic, so closely akin to dialégesthai, has been overloaded with burdens output of the ceaseless workings of a Speculative Reason, piled up throughout the centuries, it may be of some interest to reach back a concept belonging to a thought which, as Taylor puts it (Plato, The Man and His Work, London 1949, XI; it tr. p. 457), never pretended to build up a scientific conception of the world having permanent validity - to refresh air and try an ancient path in search for a new one.