 Of course, platonism about any of these kinds of objects is controversial. Many philosophers do not believe in abstract objects at all. The alternatives to platonism will be discussed in  section 2,  but it is worth noting here that the primary argument that platonists give for their view is that, according to them, there are good arguments against all other views. That is, platonists think we have to believe in abstract objects, because (a) there are good reasons for thinking that things like numbers and universals exist, and (b) the only tenable view of these things is that they are abstract objects. We will consider these arguments in detail below.