  This criticism of the scientific and philosophical use of certain ordinary terms goes along with rejection of philosophical questions which make essential use of those terms. For example, many philosophers hold that there are important philosophical problems concerning knowledge: Do we really know anything at all? What exactly are the conditions on knowledge? (This latter question has seemed especially pressing since Gettier, 1963.) Quine, by contrast, finds the word “knowledge” vague, and consequently rejects it for serious use, saying that the word is ‘‘useful and unobjectionable in the vernacular where we acquiesce in vagueness, but unsuited to technical use because of lacking a precise boundary’’ (1984, 295). Accordingly, many such questions formulated using the term may simply be dismissed, even if it remains eminently useful for making rough sorts of claim, when we say as above that scientific knowledge is not different in kind from our ordinary knowledge.