Here he is with some useful language about how science, if pressed to justify itself, couldn't do it:
If the sciences were not seen ... from the outside and in terms of their progress and results, i.e., according to a merely apparently proper but in fact wrongheaded theory of science, then it would have to become clear that every science, at its birth, has made a decision of principle and now lives on that basis, and conversely, from there each science also derives its characteristic way of going astray. It is never asked whether the sciences, either in general ... or in particular ... can actually furnish the idea of concrete research.
What does this mean? For starters it means that the pressure put on humanism to justify its existence all the time would easily cause science to collapse if the same pressure were applied.
Also unmissable: his critique of “worldview philosophizing,” in particular scientistic genres. Respect!