 In a positive vein, Suárez argues on behalf of final causes by means of a simple counterfactual argument. One might say, for instance, that someone made a journey to the store in order to buy milk. The buying of milk, then, is the final cause of that journey. If it were discovered that store had unfortunately run out of milk, then, suggests Suárez, the milk, or the buying of the milk, would remain the final cause of the action all the same; otherwise there would have been no journey. To the rejoinder that the actual cause was not the milk, but the agent's desire to buy milk, coupled with her belief that milk was to be had at the store, Suárez readily agrees—but then insists that the desire would not be the desire it was were it not a desire for buying milk. He contends, in other words, that the identity conditions of any desire to buy milk derive from the end, which is to say that final causation remains in play in the sphere of intentional action by providing the very identity conditions of the desires which serve as efficient causes of intentional action. Still, this reasoning, positive though it is, also contains a large concession: final causes are implicated in the efficient causal realm only under the aspect of intentionality. This is why Suárez ultimately concludes: