 Consider the sentence ‘3 is prime’. This sentence seems to say something about a particular object, namely, the number 3. Just as the sentence ‘The moon is round’ says something about the moon, so too ‘3 is prime’ seems to say something about the number 3. But what is the number 3? There are a few different views that one might endorse here, but the platonist view is that 3 is an abstract object. On this view, 3 is a real and objective thing that, like the moon, exists independently of us and our thinking (i.e., it is not just an idea in our heads). But according to platonism, 3 is different from the moon in that it is not a physical object; it is wholly non-physical, non-mental, and causally inert, and it does not exist in space or time. One might put this metaphorically by saying that on the platonist view, numbers exist “in platonic heaven”. But we should not infer from this that according to platonism, numbers exist in a place; they do not, for the concept of a place is a physical, spatial concept. It is more accurate to say that on the platonist view, numbers exist (independently of us and our thoughts) but do not exist in space and time.