Ostrich presentism

Ostrich presentists maintain that we can use all the expressive resources of the tensed language to provide an explanation of why true claims about the past are true, without thereby paying any price in terms of ontology or basic ideology. I clarify the position by making a distinction between three kinds of explanation, which has general interest and applicability. I then criticize the ostrich position because it requires an unconstrained version of the third form of explanation, which is out of place in metaphysics.