 The issues above look contrived and artificial to some people’s taste—even among philosophers. Many have suggested a closer look at real-world inferential practices in the sciences as a more appropriate benchmark for assessment. For one thing, the very idea of hypothetico-deductivism has often been said to stem from the origins of Western science. As reported by Simplicius of Cilicia (sixth century A.D.) in his commentary on Aristotle’s De Caelo, Plato had challenged his pupils to identify combinations of “ordered” motions by which one could account for (namely, deduce) the planets’ wandering trajectories across the heavens as observed by the Earth. As a matter of historical fact, mathematical astronomy has engaged in just this task for centuries: scholars have been trying to define geometrical models from which the apparent motion of celestial bodies would derive.