P13: An affect toward a contingent thing which we know does not exist in the present is milder, other things equal, than an affect toward a past thing.

Dem.: Insofar as we imagine a thing as contingent, we are not affected by any image of another thing that posits the thing’s existence (by D3). But on the other hand (according to the hypothesis), we imagine certain things that exclude its present existence. Now insofar as we imagine a thing in relation to past time, we are supposed to imagine something that brings it back to our memory, or that arouses the image of the thing (see IIP18 and P18 S), and therefore brings it about that we consider it as if it were present (by IIP17 C). And so (by P9) an affect toward a contingent thing which we know does not exist in the present will be milder, other things equal, than an affect toward a past thing, q.e.d.