  If we take anti-realism to be the view that (a) nothing in extramental reality corresponds to our relational concepts and (b) nothing is related independently of the activity of the mind, it is not hard to see why most medieval philosophers would reject it. Like most of us, they recognize the utter implausibility of saying that facts like Simmias’s being taller than Socrates are somehow dependent on the activity of the  mind.[15]  Indeed, as they often point out, this sort of anti-realism is inconsistent with even such basic facts as the real structure of the universe, the existence of real composition, causality, spatial proximity, or even the objectivity of mathematical knowledge. Speaking for the majority, Ockham says in his Ordinatio: