 Yet here in the Treasury Vasubandhu is only gesturing in this direction. His non-Buddhist opponents would also like to distinguish reasons from causes, so instead of attempting to unify their causal basis himself, Vasubandhu suggests that commitment to the unitary nature of divine causality commits them to conflating them. The serious point behind the opening joke, then, is that philosophy requires that we make distinctions among ideas and entities, and debate assumes differences of opinion and perspective. For Vasubandhu, such differences are evidence that it is impossible that all things have issued from a single cause. He begins, then, with a shot across the bow, which expresses just how seriously he will hold the theists to their claim that all things have one cause.