If objects in space are merely our representations, then our representations would have to be the source of the very affection that produces those representations.

Or one understands by affecting objects the objects in space; but since these are only appearances according to Kant, and thus our representations, one falls into the contradiction that the same appearances, which we first have on the basis of affection, should be the source of that very affection. (Vaihinger 1881: vol. 2, p. 53)