 (a) Firstly we can argue that if Nāgārjuna debates with an opponent who holds that since a cause has its property of being a cause essentially, its notional dependence on the effect will entail its existential dependence. For something being a cause essentially means that this is a property it could not lose without ceasing to be that very object. But since the presence of this property depends on existence of the effect, the existence of the cause as that very object also depends on the existence of the effect.