Indeed, in his (Ehrenfels 1885, Ierna 2017a) dissertation Ehrenfels presents an account of the concept of number and the philosophy of mathematics that is for the most part the traditional Brentanian one, though unsurprisingly including many Meinongian elements. Ehrenfels claims that by abstracting from all particularities of two objects and considering them merely as the foundations of a relation of difference, we obtain the concept of two. If we then add another object, we need to compare and distinguish not only the first-order relations among the foundations, but also the second-order relation of difference among the first-order relations of difference, and so on for every additional element. This leads to a rapid increase in complication, as illustrated in Husserl’s critique of such an approach in the second chapter of the Philosophy of Arithmetic. Ehrenfels likewise concludes that this process of distinction soon leads beyond our limited presentational capacities and requires more convenient, though indirect, ways of presenting numbers. Hence, he argues that higher numbers can only be reached by successive presentations of partial numbers, e.g. nine by three times three.