  Whatever its exact provenance, Vaihinger’s basic thought is that what is selected for in the evolution of our cognitive capacities is the ability to aid us in carrying out activities that are useful for the purposes of survival. Specifically, Vaihinger seems to reason that any course of action—say, procuring food for oneself—involves at least some minimal degree of planning, and that in turn requires some basic ability to predict what the future will be like, and to know how it will be different if we choose to φ rather than to ψ. Thus, he suggests that the purpose of thought is “to calculate those events that occur without our intervention and to realize our impulses appropriately” (PAO 3). For the bare purposes of carrying out those actions necessary for survival, Vaihinger is claiming, the intellect would not have to be a reliable guide to the way the world really is. On the contrary, fictions may have an indispensable role to play here.