‘Once is never’ – this phrase, according to Peter Szondi, encapsulates the golden rule of science and all verifiable knowledge in general. What occurs only once poses something intolerable and indeed impossible for scientific thinking: it cannot be verified and so escapes the order of knowledge as the ground of certainty. How can we be certain of what happens only once? Einmal ist keinmal – scientific thinking views the particular only as a specimen, a species implicitly or explicitly belonging to a genus. Knowledge is derived by inference from specific cases in respect of a general order. In the essay from 1962 entitled ‘On Textual Understanding’ it is literary criticism which Szondi charges with too readily embracing this scientific code of practice when on the contrary it should pause to consider the extreme possibility raised by the way in which tropes work in literary texts, that of existing at random and in relation to no other figural or literal moment, eluding verifiability and thus breaching scientific decorum. I will come back to this but mainly I want to follow a different set of implications provoked by Szondi's insight into science's repression of the singular, its sidelining or denial of it.