Who did Heidegger consider as the thinkers of Being in Antiquity?

Question

Following this question; and in fact the answer by Ram T.

I understand that Heidegger was interested in Heraclitus, and this by way of Holderlin; further, there are as far as I understand, a number of theories in antiquity of Being - ousia & morphe and its combination as being - the hylomorphism; this is, in some sense, a modification by Aristotle of Platos theory of Forms (he questions quite early on in the Metaphysics, on how a Form can affect sensible matter); of the apeiron of Anaximander, the elements & love/strife amongst them, atoms; H claimed that Philosophy had forgotten Being; in which case it had understood it once as a key questions - who did H consider as the key thinkers of antiquity on Being; or was merely a rhetorical strategy to get his project underway?

Answer 1

In thinking Being, Heidegger differentiates between

1. The first beginning
2. The other beginning

The first beginning starts with the ancient Greeks. They ask the question of Being (Sein), but in a specific form, namely what a being (Seiende) in essence is. In Sein und Zeit, this is called the present-at-hand (Vorhandenheit) mode. Later he calls this the beingness (Seiendheit) of being. This way of asking the question assumes the Being of being is itself a kind of a being (Seiende), namely fundamental and eternal: an essence, an idea (Plato), an ousia/morphe (Aristotle), a representation (Kant), will to power (Nietzsche) etc.

The other beginning starts with Heidegger (sort of, he usually says he's making way for it, preparing for it). Rather than (merely) thinking Being at the being present at hand, he questions Being as Being, Being as such, Being itself the clearing of Being.

The first beginning obscures the real question of Being. So they (and all other philosophers until Heidegger) are 'thinkers of Being' only in a certain limited way. The ancient Greek thinkers had an experience or insight into Being, but by asking about it in this way, this insight was obscured and soon forgotton.

Plato and especially Aristotle are the ones who pushed to formalisation of this way of thinking and are therefore presented by Heidegger as the origin of the forgetting of Being. In the presocratic philosophers (Heraclitus, Parmenides) this formalisation is less developed, and usually Heidegger hopes to find traces there of the original insight into Being, to help him with making way for the other beginning.

Answer 2

In Being and Time Heidegger sees Aristotle's physics (especially his account of time) and metaphysics as the pinnacle of ancient ontology.

Within the framework of the following fundamental elaboration of the question of being a detailed temporal interpretation of the foundations of ancient ontology-especially of its scientifically highest and purest stage, that is, in Aristotle-cannot be offered. Instead, we offer an interpretation of Aristotle's treatise on time; which can be taken as a way of discerning the basis and limits of the ancient science of being. (Being and Time § 6)

The historical scheme in Being and Time is roughly this: ancient greek thinking on Being, culminating in Aristotle, and also Aristotle's medieval followers, perfected the grasp of the present-at-hand, the objective. Modern thinking entered into the subjective realm. But still not enough. And this is where Heidegger is entering the scene.

Answer 3

the philosophy of the Greeks... came to an end in greatness with Aristotle

The presocratics were responsible for the "birth" of philosophy, according to then Historical Dictionary of Heidegger's Philosophy, anyway.

in his Marburg period (1923-8) Heidegger discerns no discontinuity between, on the one hand, Plato and Aristotle and, on the other hand, the Presocratic thinkers... Heidegger primarily focuses on Plato and Aristotle

whereas

In An Introduction to Metaphysics...Heidegger argues that the Presocratics represent the ‘Original or First Beginning,’ whereas Plato and Aristotle represent the ‘End of the First Beginning’ or, alternatively, the ‘Beginning of the Second Beginning.’

This article asks who are Heidegger’s Greeks?

It says

Heidegger’s Greeks, insofar as they are authors (and not just speakers of Greek), are the authors of a very smal selection of celebrated texts, from Homer through Aristotle, with the emphasis on the fifth century (Heraclitus, Parmenides, Sophocles) rather than on earlier or later periods