Continuing the excerpt from Appendix 8 of The Age of the World Picture.

For Protagoras, to be sure, beings remain related to man as egw. Of what kind is this relation to the I? The egw stays, in the sphere of that which is apportioned to it as this particular unconcealment. Accordingly, it apprehends everything that presences within this sphere as in being. The apprehending of what presences is grounded in this staying within the sphere of unconcealment. The belonging to the I to what presences is through this staying alongside what presences. This belonging to what presences in the open draws the boundary between what is present and what absent. From out of this boundary man receives and preserves the measure of that which presences and that which absences. In his restriction to that which is unconcealed at a particular time, man gives himself the measure which confines a self in each case to this and that. Man does not set the measure to which all beings in their being here have to accommodate themselves, out of a detailed I-ness. One who stands in the Greeks' fundamental relationship to beings and their unconcealment is metron (measure) insofar as he accepts restriction to the sphere of unconcealment limited after the manner of the I; and, as a consequence, acknowledges the concealment of beings and that their presence or absence, together with the visible appearance of what is present, lies beyond his power of decision. This is why Protagoras says (Fragment 4 in Diels, Fragmente der Vorsokratiker) peri men qewn ouk ecw eidenai, ouq wV eisin, ouq wV ouk eisin, ouq opoioi tineV idean. "Concerning the gods, I am, admittedly, not in the position to know (i.e., for the Greeks, to have something in "sight") either that they are, or that they are not, nor how they are in their visible aspect (idean)."

polla gar ta kwluonta eidenai, h t'adhlothV kai bracuV wn o bioV tou anqrwpou. "Many, that is, are the things that prevent the apprehending of the being as what it is: both the un-openness (concealment) of beings and the brevity of man's course in history.

In view of this thoughtful circumspection on Protagoras' part, it is no wonder that Socrates says of him (Plato, Theaetetus 152 b) eikoV mentoi sofon andra mh lhgein. "We may suppose that he (Protagoras), as a sensible person, was not (in his statement about man as the metron) simply babbling."

The fundamental metaphysical position of Protagoras is merely a narrowing down--which means, nonetheless, a preserving--of the fundamental position of Heraclitus and Parmenides. Sophism is only possible on the basis of sofia, i.e., on the basis of the Greek interpretation of being as presence and truth as unconcealment--an unconcealment which remains itself and essential determination of being, which is why that which presences is determined out of unconcealment, and presencing out of the unconcealed as such. But how removed is Descartes from this beginning of Greek thought, how different is the interpretation of man which represents him as subject? In the concept of the subjectum, there still lingers on the sound of the Greek essence of being (the upokeisqai of the upokeimenon) in the form of a presencing that has become unrecognizable and unquestioned (namely, that which lies permanently at hand). Precisely because of this, we can recognize in this concept of presencing the transformation of the fundamental metaphysical position.

It is one thing to preserve the always limited sphere of unconcealment through the apprehension of what presences (man as metron). It is something different to proceed into the unlimited region of possible objectification through the calculating of the representable of which everyone is capable and which is binding on all.

Every subjectivism is impossible within Greek Sophism since man can never, here, become subjectum. This cannot happen because, in Sophism, being is presencing and truth is unconcealment.

In unconcealment, fantasia happens: the coming to appearance, as a particular something, of that which presences--for man, who himself presences to what appears. Man as the representing subject fantasies, however, he moves in imaginatio in that his representation imagines the being as object into the world as picture.

The philosophical conversations blog has had a couple of posts on Protagoras through Heidegger.

This piece on the Logopolis blog via Rorty on Wolin is also interesting, and connects with Nietzsche, anticipating where this might go.  ¶ 8:24 AM