To see how this is a consequence, let us first note how it is possible to provide a definition of converse in terms of the standard notion of exemplification; for, given any binary relation, we may define a converse relation to be one that holds between the objects a and b just in case the given relation holds between b and a.(1) But once given an intelligible notion of converse, it is very plausible to suppose that each relation has a converse.
"Converse Relations." Philosophical Review 94:249-62.
But, similarly, the converse relation
should correlate a lower-level G in one-many fashion with a range of upper-level properties E through F such that, minimally, it is possible for an instance of G to subserve an instance of E and not F, and on another occasion, F and not E (the system which is an Intel 80486 microprocessor (G) might instantiate the adding function (F) and not the tangent function (E), and vice versa).(6) So, given the same determinative connection, one must say:
First, for any relation there is a converse relation
and it is not clear what they would be in these cases.
Are Necessary and Sufficient Conditions Converse Relations