H. P. Grice: it seems to me very important that, when one is considering this sort of thing, one should take every precaution to see that one isn't taking things for granted and that the concepts which one is going to use have, as their basis, concepts which will only bring in what is required for them to do whatever job it is that one wants them to do.

 it seems to me very important that, when one is considering this sort of thing, one should take every precaution to see that one isn't taking things for granted and that the concepts which one is going to use have, as their basis, concepts which will only bring in what is required for them to do whatever job it is that one wants them to do.