I tend to think that these abstracts exist outside of our minds. We didn't create them; we discovered them and we set to explicate them. Einstein's was a discovery within the larger discovery that we attempt to explicate and call mathematics.
I think that the problems lie in the disconnect, infinitesimally small, or large depending on one's point of view, between these abstract things, and our atempts to explicate them, to put our finger on them, as it were.
In regard to morals, I think that there is something that compels us to behave in ways that ensure, on the one hand, our individual welfare, and on the other hand, the welfare of the group within which we find ourselves. This is but one dynamic within the thing we attempt to explicate and call "morals."
(Apologies for any bad grammar and spelling. I'm writing this on a cel. phone, and lack the facility of a spell checker.)