 It should be mentioned, though, that the key idea behind the way of abstraction has resurfaced (though transformed) in the structuralist views about mathematics that trace back to Dedekind. Dedekind thought of numbers by the way of abstraction. Dedekind suggested that when defining a number-theoretic structure, “we entirely neglect the special character of the elements, merely retaining their distinguishability and taking into account only the relations to one another” (Dedekind 1888 [1963, 68]). This view has led some structuralists to deny that numbers are abstract objects. For example, Benacerraf concluded that “numbers are not objects at all, because in giving the properties (that is, necessary and sufficient) of numbers you merely characterize an abstract structure—and the distinction lies in the fact that the ‘elements’ of the structure have no properties other than those relating them to other ‘elements’ of the same structure” (1965, 70). We shall therefore turn our attention to a variant of the way of abstraction, one that has led a number of philosophers to conclude that numbers are indeed abstract objects.