Why must the redness that isn't in the rose be in the head? The unexpressed assumption is that the redness that seems to be in the hallucinated rose really exists somewhere. Now, the only reason to think that it exists is that it seems to be there, and when I say "there" I mean in the rose: that is
where it seems to be, right? But,
ex hypothesi, that very seeming is illusory in this case. That's why we call it a hallucination. So there is no undefeated reason to think that that instance of redness exists at all. Goff here begs the question, because he assumes that qualitative redness exists whenever someone has a subjective experience seeming to be of a red object; this assumption is plausible only if you already think that redness is a subjective quality.
Goff might respond by saying that even if the redness in a hallucination does not exist, the
appearance of redness does, and that appearance has the same character as genuine redness, leading to all the same problems.
But this would be a confusion. The claim that the appearance has the same character as genuine redness, in the sense in which it is reasonable, means only that the apparent rose seems the same as a real rose: the way the non-existent rose
seems, in regard to its color, is just like the way a real red rose
seems. But from this statement about how things seem nothing follows about how things are. Or rather, the only thing that follows is that the seeming itself occurs and has the character that it does, which provides us with another way of taking the claim that the appearance has the same character as genuine redness: that the subjective quality of what it is like for me to see the red in the hallucinated rose has the same character as seems to be in a real rose. But in this sense the claim is unreasonable. What the appearance of hallucinated redness is the same as is not genuine redness, but
appearances of genuine redness; which is to say that the introspectable quality of the seeming is the same in both cases. But the quality of a seeming is not the same as the quality that seems to be in the thing seen. The latter quality, redness, is known not by introspection, but by extraspection. The former, introspectable, quality, what it is like for me to see red, is not something that ever seems to be in an inanimate object. The naïve realist thinks that extraspection, like introspection, normally puts me in direct contact with its objects and their qualities. But on anybody's view, there is an evident difference between introspection and extraspection. Extraspection at least seems to acquaint me with objects distinct from myself. Introspection never even pretends to do that.
Or does it? It occurs to me that there is a third interpretation of the Galilean move that I have neglected to mention, a historically important one. On this interpretation, whenever I seem to be directly aware by extraspection of a red object, I actually am directly aware of an object, a really existing object, but existing in a kind of mental theater, and I am infallibly aware of the directly perceived qualities of that object. My naïve mistake is in thinking that that object and its qualities have any existence when not being perceived by me. I can infer the existence of other, unperceived, entities that are in causal relation to the perceived furniture of the theater of the mind, but those inferred causes are not themselves perceptible, strictly speaking.
One possible factor influencing the early modern philosophers in this direction may have been their failure to reckon with the intentionality of experience. If one tries to explain the relation between the thing perceived and the perceiving of it on the model of transitive actions of the physical sort (as Galileo understood the physical), one discovers that the existence of a transitive action entails the existence of the thing acted upon. If one billiard ball strikes another, the other ball exists. Thus one is led to think that if I hallucinate a rose, the thing hallucinated must exist. Since obviously there is no real rose present, the hallucinated thing, which I take for a rose, must really be something else: the idea, or image or impression of a rose.
It's my understanding that this theory has fallen very much out of favor, and for good reason. I don't think Goff is deliberately trying to revive it, but perhaps it has some residual influence on his thinking. That would explain his twin mistakes: like the early modern philosophers, his phenomenology is, perhaps, innocent of intentionality (maybe that's why he takes for granted that hallucinated redness must really exist somewhere). And, like them, he thinks the character of redness that seems to be in things is really "in the head," perhaps meaning not that it is in the mind subjectively, as what it is like for me to see red, but that it is in the mind objectively, as a feature of a denizen of the theater of the mind; that would explain why he thinks the mental quality in the hallucination has the same character as what naïve common sense takes to be in a rose in veridical experience.
If this is what he is thinking, then what he needs to do to convince the naïve realist is not to explain why redness is in the mind. The naïve realist already agrees with him that redness is in the mind objectively when it is perceived. What he needs to do is to explain why things that are in the mind objectively in this way cannot exist when not perceived.
But I don't think this is really what Goff is up to. In his response to Feser, he writes,
If I’m hallucinating a red rose, then there’s no red rose out there in the world for me to be related to. So when it comes to hallucinations, at least, the experience must be in the head. The direct realist, then, is led to the view that veridical experiences ... are radically different kinds of things from hallucinations: the former are world-involving relationships, the latter are in the head. This view is known in philosophy of perception as ‘disjunctivism.’
Note that now, his premise is not that, in hallucinations, the secondary qualities are in the head, but that the
experiences are. The premise of his prior argument (that, in hallucination, redness is in the perceiver), if accepted, would force us naïve realists into a radical disjunctivism in order to maintain our belief that, in ordinary perception, redness occurs in objects existing independently of the perceiver. But we are not forced into such disjunctivism by the claim that the
experience is in the perceiver. We already think perceptual experiences are in perceivers. At least the subjective part of an experience is there. Some naïve realists may develop their views by claiming that an experience is an integral whole that includes both subjective and objective parts or aspects. (Since 'experience' is not a term of art in Aristotelian philosophy, Feser and I don't have any prior commitments regarding its "location.") But in any case, there is no need for us to posit a radical difference between what is subjective in the true and the hallucinated experience. Thus our position is untouched by Goff's attack on disjunctivism:
Consider a moment when Sara is veridically seeing a red rose at precisely 2pm. Now let’s imagine a genius evil scientist kidnaps Sara later that day, removes her brain and puts it in a vat, and then fiddles with it so that it’s in the exact same state it was at 2pm that day. Presumably, Sara’s brain in the vat will now be having an internal experience that makes it seem to her that it’s seeing a red rose (even though the brain doesn’t have any eyes, so isn’t seeing anything). But, given that at 2pm Sara’s brain was in the same state, then her brain at 2pm must have also generated an internal experience that made it seem to Sara that she’s seeing a red rose. Strictly speaking this doesn’t rule out direct realism: at 2pm Sara’s brain might have generated an internal experience (that made it seem to her that she’s seeing a red rose) and in addition Sara might have also had a world-involving experience (that also made it seem to have that she’s seeing a red rose). But the latter experience seems redundant ...
There is no "in addition." The naïve realist can say that that very same "internal" experience (as Goff calls it) occurring at 2pm is not
merely internal but also world-involving. What was contributed to the experience by Sara's brain at 2pm was indeed identical (abstracting from how it was related to things outside Sara) with what occurred when she was in the vat. But nothing prevents those subjective realities in Sara from being part of a larger integral whole at one time, and not at another. For what distinguishes merely internal from world-involving experiences depends on more than just what goes on in the brain.