 Aristotle is the first Greek author to mention the sciences of optics and mechanics, describing optics as a subordinate science to geometry and mechanics as a subordinate science to solid geometry (APo. 78b34). Archytas does not mention either of these sciences in B1, when describing the work of his predecessors in the sciences, nor does Plato mention them. This silence suggests that the two disciplines may have first developed in the first half of the fourth century, when Archytas was most active, and it is possible that he played an important role in the development of both of them. In a recently identified fragment from his book on the Pythagoreans (Iamblichus, Comm. Math. XXV; see Burkert 1972a, 50 n. 112), Aristotle assigns a hitherto unrecognized importance to optics in Pythagoreanism. Just as the Pythagoreans were impressed with the fact that musical intervals were based on whole number ratios, so they were impressed that the phenomena of optics could be explained in terms of geometrical diagrams. In addition to being an accomplished mathematician, Archytas had a theory of vision and evidently tried to explain some of the phenomena involved in mirrors. In contrast to Plato, who argued that the visual ray, which proceeded from the eye, requires the support of and coalesces with external light, Archytas explained vision in terms of the visual ray alone (A25). It is tempting, then, to suppose that Archytas played a major role in the development of the mathematically based Pythagorean optics, to which Aristotle refers. On the other hand, when Aristotle refers to Pythagoreans, he generally means Pythagoreans of the fifth century. Elsewhere he treats Archytas independently of the Pythagorean tradition, writing works on Archytas which were distinct from his work on the Pythagoreans. It would thus be more natural to read Aristotle’s reference to Pythagorean optics as alluding to fifth-century Pythagoreans such as Philolaus. Archytas will then have been responsible for developing an already existing Pythagorean optical tradition into a science, rather than founding such a tradition.