“Martin Heidegger was opposed to all metaphysical claims in principle.”

The driving question in Heidegger's work is “the question of being”—the question of the meaning or sense of being—and he argued that our understanding of being is temporally structured. In Being and Time, Heidegger pursued the question of being by means of a phenomenological exploration of the way that time structures our engagement with the world. Heidegger was an ontological pluralist: he held that there are multiple distinct kinds of being.

Heidegger's critique of metaphysics is not a rejection but a transformation of its role. He aims to uncover the limitations of traditional metaphysical thinking and open a path toward a more fundamental ontology, where being is no longer taken for granted but approached as an unfolding mystery that demands a more humble and thoughtful engagement.

Heidegger's disavowal of the word “metaphysics” was in part a rhetorical response to Carnap, but it also marked the beginning of his substantive critique of “representational” or “calculative” thinking. Heidegger's later thought aims at an “overcoming of metaphysics” – not in Carnap's sense, but rather to think not just the meaning of being, which is to say being understood as the being of entities, but the truth of being, that is, the way in which being as such manifests itself.

Heidegger's most significant critique of metaphysics is that the history of metaphysics is the history of the forgetting of being. However, he also criticizes metaphysics for forgetting the nothing. Metaphysics fails to adequately address both being and nothingness, neglecting the nothing and treating it as a conceptual abstraction without objective reference.

Martin Heidegger's Being and Time offers a sustained critique of the Western philosophical tradition. Specifically, Heidegger describes his project as a 'deconstruction' of prior ontological systems, whose goal is a positive recuperation and reformulation of the 'question of being.' Heidegger's metaphysics is delineated point by point in a critical or contrapuntal mode, positioned against the work of various canonical figures; it is by means of critique that his positive vision emerges.

According to Heidegger the basic error committed in connection with the question of Being stems from what he calls metaphysical thinking, which is a way of thinking we come across all along the history of philosophy. This way of thinking always asks "what is Being?", which is a wrong way of putting the question of Being; it has never asked what the meaning of Being is.

Heidegger's entire philosophy, including his effort to overcome or get free of metaphysics, begins and ends with his radically new vision of human being. He argues that metaphysics, both ontology and natural theology, has forgotten about the clearing, which is the very basis of all human knowledge and activity.

Heidegger has rejected understanding beings as mere objects standing over against a subject as a derivative and misleading assumption, and his references to Being are not to a being. So 'being lasts as the withdrawing-proferring' must refer to an ultimate source of meaningfulness that emerges historically, contingently, in a way that orients Dasein but cannot be determinately discriminated.

Heidegger's critique of metaphysics is regarded as the most systemic and comprehensive ever written; he thought through “limits” within logical sets and challenged the meaning of structural mindsets.

For Heidegger, much of the history of philosophy has focused on this beingness rather than inquiring into the happening of Being itself. Heidegger tries to reawaken the "question of Being" by challenging some of the most enduring prejudices embedded in Western philosophy and in our everyday practices and language.

But rather than rejecting metaphysics out of hand, the early Heidegger argues for the need to ground metaphysics in general on the foundation of a metaphysics of Dasein (see, e.g., GA28:41ff.). Dasein's ontology will sustain a fundamental ontology because Dasein is a temporal being-in-the-world, and thus the entity with an understanding of being.

Heidegger revisits German idealism after the 'turn' in his thought in the mid-1930s. Heidegger does not like value philosophy, whether in its Platonic or Nietzschean forms, but this represents a critique of specific metaphysical traditions rather than metaphysics as a whole.

I don't think of Heidegger as a postmodernist but rather as a last step to postmodernism. Two differences strike me as significant. (d) Heidegger is doing metaphysics, and speaks of there being a truth out there about the world that we must seek or let find us, while postmodernists are anti-realists, holding that it is meaningless to speak of truths out there or of a language that could capture them.

In response to the limitations of metaphysics, Heidegger proposes a new way of thinking, which he calls 'meditative thinking' (besinnliches Denken). This thinking does not seek to dominate or explain being but to listen and attune itself to the way being reveals itself. This involves what Heidegger calls a 'step back' from metaphysical thinking to an openness to the mystery of being.

Heidegger takes it that metaphysics thinks Being, but not as Being (beings qua beings, as opposed to Being qua Being). Rather, it thinks Being through thinking beings as a whole. Indeed, Heidegger thinks that it is through asking what metaphysics is that we begin to think Being properly, as that which grounds metaphysical thought without itself being thought explicitly by it (this is the premise of 'What is Metaphysics?').

Heidegger developed his own ontological system, particularly in Being and Time, which he called 'fundamental ontology.' This was itself a metaphysical project aimed at reformulating the question of Being, demonstrating that Heidegger did not reject metaphysics in principle but rather sought to transform and overcome what he saw as distortions in the Western metaphysical tradition.

Heidegger's later philosophy has often been regarded as a lapse into unintelligible mysticism... his notion that overcoming 'oblivion of Being' is the essence of a turning to a post-destitute, genuinely post-modern existence.

Although Heidegger initially informs us that we were to let ourselves be transposed directly into metaphysics, he instead shows that this is actually not possible because as long as human beings exist, philosophy and metaphysics occur also - “we are always already within” (96) metaphysics.