OK, I recently read Philosophical Investigations and I enjoyed it very much! Language games! Anyway, I wanted to quote a passage about mathematics

But am I trying to say some such thing as that the certainty of mathematics is based on the reliability of ink and paper? No. (That would be a vicious circle.)–I have not said why mathematicians do not quarrel, but only that they do not.

It is no doubt true that you could not calculate with certain sorts of paper and ink, if, that is, they were subject to certain queer changes—but still the fact that they changed could in turn only be got from memory and comparison with other means of calculation. And how are these tested in their turn?

What has to be accepted, the given, is—so one could say—forms of life.

Makes you think, right?