ABSTRACT. Brown says that the meaning of a mathematical expression cannot be located as an entity "outside" language. Ortiz et al. affirm that when children are first taught probability, they have frequently used terms and expressions to refer to randomness, sometimes with a meaning different to what is usual in the mathematics classroom. Wigner holds that it is unquestionably true that the concepts of elementary mathematics were formulated to describe entities which are directly suggested by the actual world. Katz emphasizes that there is no reason to think that scientific psychology cannot explain the rational faculties on which our account of mathematical knowledge is based.