   Again, as we shall point out in the next section, a number of later medieval reductivists, including Ockham, eventually come to reject the traditional Aristotelian characterization of relations as items that relate substances in favor of the view that relations are items existing only in the mind (as concepts). As we shall see, this does not mean that Ockham and others deny that there are extramental grounds for our relational concepts or even that things can be related by their foundations independently of the mind. On the contrary, it means only that, unlike their predecessors, they refuse to call anything a relation merely because it grounds a relational concept. The fact that these reductivists regard relations as concepts, however, explains why they too are unwilling to identity relations with their foundations: for the relevant foundations, according to these philosophers, are ordinary, extramental accidents, and obviously no concept (or act of the mind) could be identical with them.