Quine wrote in his 1951 paper "Two Dogmas of Empiricism":
"Physical objects are conceptually imported into the situation as convenient intermediaries not by definition in terms of experience, but simply as irreducible posits comparable, epistemologically, to the gods of Homer [...]. But in point of epistemological footing, the physical objects and the gods differ only in degree and not in kind. Both sorts of entities enter our conceptions only as cultural posits."
This was intended as an illustration of the idea that all statements are theory laden - no fact is ever independent of linguistic (and therefore cultural) artifacts. It points to the difficulty of telling the difference between good science and bad science vs good science and non-science.
But then doesn't Quine imply here that the Homeric deities have some predictive power compared to physical models?
Can't someone refute Quine's argument by pointing out that Homeric mythology has zero predictive power, whereas physical theories, no matter how imperfect, do succeed at least at predicting somethings some of the time?
Or looked at from the opposite direction, the authors of "Harry Potter" and "Lord of The Rings" never claimed that their fiction ever had any predictive power. Many would consider Greek Mythology to be in same category as those two.
If Greek Mythology had 10% predictive power while modern physics had 70% predictive power, one could argue that physics and Homeric deities "differ only in degree and not in kind". But the fact that Homeric gods have 0 predictive power, compared to the predictive power of even the most outdated empirical physics model means that they are of different kinds, not just different degrees.
How does one interpret Quine in light of this reasoning? Does he seriously think that Homeric gods have some, albeit very small, predictive power? Or is the fact that some concepts are pure fiction (Home as story teller like Tolkien or Rowling) while others are empirically based irrelevant to his confirmation holism?