On the claim of science.

For Heidegger, “each supposition is always already grounded in a certain kind of acceptio. Only when the presence of something is accepted, can one have suppositions about it.” It is in this sense that Heidegger introduces the distinction between perceptible, ontic phenomena and the “imperceptible, that is the existing of something = ontological phenomena” that “always already and necessarily show themselves prior to all perceptible phenomena.” The point itself is key to “the contrast between the psychodynamic and the Daseinsanalytic view of the human being” and to that extent Heidegger reflects on what must be assumed, taken as given in order to articulate the Freudian schema whereby, as Heidegger explains, phenomena will be required to “take a backseat to suppositions” for Freud just to the extent that Freud is concerned with tracing causality of a scientific kind apart from what is otherwise given to be seen: the unconscious, in other words, which as Heidegger points out counts as such for Freud as “only that which can be explained in terms of psychological, unbroken, causal connections between forces is actual and genuinely actual.”

The claim is the claim of science: this is what is meant by what is “real and truly existent” for Freud. Here Heidegger immediately draws a parallel to Planck in another context, referring to physics, the essence of the scientific: “Only that which can be measured is real.” Heidegger’s counterpoint, contra Planck but also contra Freud is to point to an ineffable otherwise: “Eine Trauer zum Beispiel.” I find it helpful to hear in this an allusion to Hölderlin’s Sophocles, which concludes a poetic word as a ‘measure’ to articulate joy.

From Babette Babich's "William J. Richardson, S.J. and the Spelling of Marilyn Monroe: On Truth, Science, and the ‘Unfolding of Man’ in Heidegger and Lacan".