In short, I don't think there is such a thing as abstract things. They're real and measurable, as jots on a piece of paper, on a computer screen, spoken as words - and ultimately as jigglies of some kind within a human brain, which is in a body which is acting in the world. The separation between the two, I believe, is artificial. And yes, this does, in some sense, make everything real that we can conceive - in *some* fashion, because we're not conceiving of things from outside of this Universe but from within it.