All begin with a comprehensive image of the universe and of man's place in it. The starting point should be Dasein, the concrete embodied existence of an individual anxious about adapting, getting by, achieving authenticity. His tortured terminology: 'ontic' vs. 'ontological ', 'existenziell' vs. 'existential', ready-to-hand' vs. 'present-to-hand' are all intended to break the intellectual stranglehold of the detached observer and his forgetfulness of the being of being.
Heidegger's goal was the utter destruction of traditional metaphysics by exposing its withered roots. Suppose we grant his point. Any metaphysical system constructed from the viewpoint of the detached observer contemplating objective reality is fundamentally flawed. Yet, classical physics was constructed in just this perspective. The bearing this criticism has on the appraisal of physics depends on how one relates physics to philosophy. Heidegger indirectly treated this in his appraisal of Kant. Heidegger used Kant's efforts to examine whether a critical appraisal of the ground and status of the concept 'object' allowed the possibility of a type of knowledge of reality different from and more basic than physics. The two differed in basic attitudes. Kant embraced physics and attempted to give it a more secure critically justifiable foundation. Heidegger regarded physics as embodying a derivative and even degenerate type of knowledge and sought something better. As Macomber (1967, pp.201-202) noted in his critical study:
All of the characteristics which Heidegger attributes to science--impersonality, flattening, self-coordinating teamwork, and the vanishing source of meaning--we have already encountered in one form or another in our discussion of decadence. There can be little doubt that Heidegger regarded science primarily--almost exclusively--as an expression of decadence.
I will simply indicate the changing status of the concept 'object'. Kant taught that we think objects by imposing on the given of sensual perception forms of sensibility, the schematism of the imagination, the categories of understanding, and the transcendental unity of apperception. The result is ontic knowledge, in Heideggerian terms. Here 'ontic' should be roughly equated with the customary use of 'descriptive metaphysics' or 'ontology' (as opposed to speculative metaphysics), i. e. a making explicit of the type of objects countenanced by the conceptual system or theory we bring to experience. Heidegger sought to get beneath this subject-object level. Our primordial experience of reality is not through a categorization of objects of experience, but through our sheer bodily presence, our being there. The analytic of Dasein, accordingly, supplies the only transit from ontic to ontological knowledge.
Heidegger's sporadic attempts to develop proper ontological knowledge is not our immediate concern. I will comment on only one aspect of the differences between the bases of ontic and ontological knowledge. In Heidegger's view, the possibility of the latter requires a primordial regression to the ground of the essential unity of ontological knowledge (Heidegger, 1968, p. 93). Hence, Heidegger's repeated strivings to get beneath the conceptual, or what can be expressed, to the pre-conceptual: the intuition that precedes knowledge as representation; the poet's insight grounding his novel use of language; the pre-Socratic intuition of a wholeness that preceded the divisive articulation of Plato and Aristotle; and, unfortunately, the belonging to a Folk that precedes citizenship in a constitutional state. Such efforts did not lead to evaluations of physics as such, but to criticisms of the dehumanizing effects of technological societies.