As soon as it is held that any belief, no matter what, is important for some other reason than that it is true, a whole host of evils is ready to spring up.
Bertrand RussellFormality Thus the absence of all mention of particular things or properties in logic or pure mathematics is a necessary result of the fact that this study is, as we say, "purely formal".
Bertrand RussellThe demand for certainty is one which is natural to man, but is nevertheless an intellectual vice.
Bertrand Russell