“ A little learning is not a dangerous thing to one who does not mistake it for a great deal. 对一个不把一知半解当作大事的人来说,一知半解并不危险。 William Allen White 威廉·艾伦·怀特
“ The meaning of a proposition is the method of its verification. 命题的意义是其验证的方法。 Moritz Schlick 莫里茨·石里克