Because I think this is an important issue, and because we're trying to be philosophically precise in this thread, I would word that slightly differently in order to preserve the very important distinction between subjectivity and objectivity. I'd say that what was verifiably real -- objectively real -- was a woman named Joan who seemed to be sincere, and who said she was having a subjective experience which she said were voices, and she acted in accordance with what she said her voices told her. We can never objectively verify the truth of her claims about hearing voices, but we certainly can verify her actions -- to the extent that anything can be historically verified. It certainly seems as if she sincerely believed she was hearing voices, and maybe she was; but we will never know.
Agreed, Patrick. With one small addendum -- we are probably entitled to think that something definitely happened to Joan, though we don't know exactly what it was, or if it was as she described it -- i.e., the Voice of God. For all that her experience was "subjective," the objective effects were truly astonishing, utterly extraordinary -- utterly inexplicable by any physical cause that we know of. That is, this insular, ignorant, inexperienced country girl somehow acquired the virtues of a successful military commander -- seemingly "overnight."
I can't explain this by means of any kind of rational proof. But there it is all the same.
Adler begins [in Ten Philosphical Mistakes] by reexamining John Locke's postulate that our ideas (derived wholly from our sensual perceptions) indirectly refer to the world, yet at the same time they are subjective and arise individually in our consciousness. In Locke's words, ideas are "objects of understanding" that fill men's minds when they think. The mind processes sensual perceptions and comes up with ideas. While "the world" that the mind thus processes remains a constant (an important interpretation of Adler's, one that places him squarely outside the postmodern camp), the "ideas" airse individually, and thus there is no guranatee that your ideas will be similar to mine. There seems to be a contradiction here, sys Adler: the private experience of processing sensual perceptions cannot gurantee that the "ideas" will be the same for you and me. If one accepts Locke's terminology, one has to accept the proposition that everyone has a different set of ideas, rendering communication virtually impossible, and yet, we do communicate.Adler's way of dealing with theis paradox is to consider ideas as the means by which we apprehend objects that are not ideas. He points out that Locke's usage is imprecise: ideas are not objects of apprehension but only tools by means of which we apprehend "objects of thought." Ideas are signs that point us to objects of thought and to the real world. "We apprehend objects of thought, but never the concepts by which we think of them."
The "splitting" of Locke's ideas into objects of thought and signs by means of which we apprehend these objects of thought allows Adler to avoid the abovementioned contradiction between subjectivity of thought and objectivity of the world. Without this distinction, Locke's (and Hume's) positions lead either to skepticism concerning the possibility of acquiring any knowledge common to all, or to solipsism (as in those linguistic theories that assert that language is ultimately self-referential and it says nothing about the world; indeed the experience of "the world" is a purely subjective experience). This skeptical and subjectivist approach has dominated twentieth-century philosophy, and it allowed for the appearance of such ultimate skeptics as Jacques Derrida or Richard Rorty. We have grown so accustomed to the minimalists yields offered by the recent philosophers that we came to believe with Soren Kierkegaard that religious faith requires an irrational leap, and that religion is private and subjective.
Adler points out that the disitnction he proposes allows us to avoid the pitfall of subjectivism and skepticism and express in theory what we kinow from practice: that common knowledge is indeed possible, that when two peope look at an object and think about it, they are thinking about the same object, even though their ideas may differ. Thus Adler returns to the famous maxim of Thomas Aquinas who was the first to emphasize that our ideas are that by which we apprehend, not that which we apprehend. This is not splitting hairs. This is fundamental.