This post doesn’t belong on an audio forum, so I should just resist the temptation of weighing in. But I can’t.Great post thanks...
First, Quine’s point (in "Ontological Relativity," from which comes the "Gavagai" coinage), as well as in several other places, is just that our best scientific theories should govern our ontology. This is a fancy way of saying that if an accepted and useful scientific theory demands that we regard a given theoretical construct as "real," then we should do so. As David Lewis put it, although "sets" were "unknown to Homo javanensis," they are nevertheless indispensable in modern mathematics and therefore should be regarded as "real." This question dates at least to Plato, for whom numbers were more "real" than the things of perception they enumerated, being pure intelligible entities not subject to perspective, change over time, and so forth. Which is to say that, although they proclaim themselves to be "empiricists," Quine, et al., are really committed to idealism—to the "reality" of non-empirical theoretical entities.
This insight dovetails with what I think mahgister was trying to say in citing Goethe. But Goethe’s view just follows Kant: the "real" is always already a construct of consciousness—of perception, which is sense information processed and interpreted by the mind. The real "in itself" is simply unknowable. Thus, Goethe says that perception is already "theoretical": "Alles vergängliche / Ist nur ein Gleichnis." This insight makes it exceedingly difficult to know where to draw the lines between the "real" and the "imaginary"; in effect, the real IS what "imagination" constructs for experience. But that is NOT to say there is no independent reality "in itself"; rather, we just don’t know anything about it except insofar as we experience it (that is, insofar as it becomes mental).
It feel good to be understood sometimes here....
For your remark about where we "drew the line between the real and the imaginary" everybody must read the greatest underestimated Goethean Scholar which is Cassirer and his "symbolic forms" books....Cassirer born a Kantian pupil become a Goethean reader all of his life....And remember that Goethe was a Spinoza admirer....
My deepest respects...