Parmenides: The Morning Star is the Evening Star

Today at 2 pm in Aquinas Hall, CUA:

Alexander P.D. Mourelatos
University of Texas at Austin
"Parmenides, Astronomy, and Scientific Realism"

Parmenides of Elea (early 5th century BC) composed a poem in two parts, "Truth," and Doxa, "Opinion." "Truth" offers an a priori deduction of the defining criteria of "what-is" or "the real," including such counter-intuitive criteria as "indivisible, unitary" and "immobile"—criteria no observable entity could possibly meet. Doxa is explicitly branded by Parmenides as a scheme that is "off-track," "deceptive," and "lacking genuine credence." Even though Doxa is considerably more fragmentary in our sources than "Truth," it is clear that Doxa comprised a full-fledged cosmology. Most surprisingly for a doctrine disparaged by its own author, it propounded breakthrough astronomical discoveries—notably, that the Morning Star and the Evening Star are the same celestial object, and that the moon gets its light from the sun; perhaps also that the cosmos and the earth are spherical.

Are there appropriate analogues in modern philosophy for this paradoxical juxtaposition of "Truth" with "deceptive Opinion"? Kant's doctrine of a duality of "things-in-themselves"(or "noumena") and "appearances" (or "phenomena") has been cited in this connection. A better model is found in a twentieth-century doctrine of scientific realism, which holds that ultimate reality is disclosed through the theoretical and postulational schemes progressively worked out by modern science. In accordance with this model, our familiar and empirically-grounded image of the world, conceptually sophisticated and scientific though it is (as was Parmenides' Doxa), is in principle replaceable by, or eliminable in favor of, postulational schemes which (like Parmenides' "Truth") defy familiar and ordinary intuitions.