It’s a post in a BSD blog, specifically of the author of The Book of PF, that is in its entirety concerned with the question of whether a new edition of The Book of PF is coming. It’s not an ad in a computer magazine. It’s fair to presuppose that a reader of the blog knows what The Book of PF is. (It’s then arguably not fair to post it for a general audience on HN, but the author can hardly control that.)
Please don’t assume everybody who presupposes knowledge does so to assert their intellectual superiority. Presupposing knowledge is how we can communicate anything at all in a culture where one can be a dozen inferences or a couple of years of learning away from even understanding a question. And people who assert their intellectual superiority usually aren’t worth listening to at all—so if you end up concluding that every smart person is doing it, or even most of them, or most of them in a field, then you have a wide-ranging misunderstanding of some sort. This, about presupposing knowledge, is one that could be. (Another popular one is not understanding that, in mathematics, “obvious”, etc., does not mean “skill issue if you don’t get it” but rather “you’ve missed something important if you don’t get it, go back and think on it some more”.)
Please don’t assume everybody who presupposes knowledge does so to assert their intellectual superiority. Presupposing knowledge is how we can communicate anything at all in a culture where one can be a dozen inferences or a couple of years of learning away from even understanding a question. And people who assert their intellectual superiority usually aren’t worth listening to at all—so if you end up concluding that every smart person is doing it, or even most of them, or most of them in a field, then you have a wide-ranging misunderstanding of some sort. This, about presupposing knowledge, is one that could be. (Another popular one is not understanding that, in mathematics, “obvious”, etc., does not mean “skill issue if you don’t get it” but rather “you’ve missed something important if you don’t get it, go back and think on it some more”.)