 These principles are primarily employed by these three thinkers in connection with numbers. But there are two ranges of number operating in Aristotle’s discussions (see Metaphysics I 6, XIII 8–9). There are what he refers to as formal numbers, one for each numeral; these are the (Platonic) Forms for numbers. But since there is only one for each numeral, and a mathematician has to be able to add two and two to get four, there is another range of numbers required: the mathematical numbers, indefinitely many for each numeral n, each of the indefinitely many a collection of n units. As Aristotle has it, Plato accepted both ranges, and Speusippus only mathematical numbers; Speusippus, then, rejects Plato’s Theory of Forms and specifically his belief in formal numbers.