Iris Young's "Throwing Like a Girl" is a wonderful description of gendered experience. Our experiences of the world are influenced by many factors that have to do with our positions in the world, both our physical positions (biological sex, physical disabilities) and our political positions (race, gender, social class, power). "Experience" is defined broadly to encompass all we are conscious of (some call it phenomenological experience). I recommend Kay Toombs work on the phenomenology of disability as another rich description of perspective.
You are right that we seek to alter our experiences in the world with the use of art, music etc. And insofar as drugs attempt to alter experience and give us new experiences, I agree with you that there is nothing wrong with them. More than that--drugs may be valuable because of the aesthetic and other pleasures they can produce. However, I think those who worry about "altered perceptions of reality" may be concerned that the drug user may be evading responsibilities when they get high ("I don't need to do my work, take care of my kids etc. because life is more interesting on LSD"). Or the drug user may behave when high in a way which does not cohere with his/her values. That is, the objections to drugs seem to me to be ethical rather than epistemic. In addition, the health risks (psychological and physical) of consciousness-altering drugs should be taken into account (another ethical concern). The word "real" is not helpful in this discussion, because it is used to mean so many different things (e.g. what actually exists vs. what matters).
If you wanted to say something in favor of this view, you might point to the absence of observed discrepancies between what we all believe and the truth. But, on reflection, this isn't a strong argument because there are observed discrepancies between what is commonly believed now and what was commonly believed at some earlier time. At the earlier time, p was commonly believed. Now not-p is commonly believed. If what's commonly believed were true, then both p and not-p would be true. But p and not-p cannot both be true. Therefore it is not the case that whatever is commonly believed is true.
Now you might say that what you mean is that truth is nothing more that what's commonly believed throughout the ages, the future included. So here is an argument against this revised view. There are lots of propositions about which there is no common belief shared throughout the ages: neither p nor not-p have been commonly believed. Does it follow that neither p nor not-p are true? For example, it has not been commonly believed throughout the ages that the sun is larger than the moon. Nor has it been commonly believed throughout the ages that the sun is not larger than the moon. Would you then want to conclude that neither belief is true: it is not true that the sun is larger than the moon and also not true that the sun is not larger than the moon?
What's outside the agent's control is, I think, somewhat narrower than what you call "perceptions or cognition." Suppose new DNA evidence reveals that a black man on death row is actually innocent. And suppose the jurors who declared him guilty say that they couldn't help seeing him as guilty when he was brought before them. I think we should be most reluctant to accept this excuse. Perhaps they could not have avoided a certain negative emotional rection to the accused (given the racism of their society and upbringing). But perceiving a person as guilty (of some crime) involves a good bit of judgment on the basis of testimony and other evidence. And here we can examine whether the jurors weighed the evidence carefully, deliberated thoroughly, and so on. As a juror one is not bound to let one's emotional reactions prevail. One can, and one ought to, try one's utmost to put these reactions aside and to judge the case on the basis of the evidence alone.
Now let's look at the narrower question whether we can be morally responsible for our immediate emotional reactions, for the "gut" dislike we sometimes experience for people with certain characteristics. Your argument for a negative answer -- such reactions are not sufficiently under our control -- is plausible when one considers merely the time at which the emotional reaction occurs: at this moment one indeed cannot avoid having it. But when you take a larger time frame, then the reaction is avoidable: when one finds oneself disliking people of a certain kind, then one can make an effort to get to know some of them, for example, and to try to form relationships and friendships that may gradually transform this emotional reaction. (Or may not: you may never be able to shake off your negative emotional reaction to educated people who manifestly don't care about their over-sized ecological footprint.) Those who never make such an effort can be morally responsible for their unwarranted negative emotional reactions.
Consider this parallel case. A driver hits a child that is running across the road. The driver says that he should not be held morally responsible for the accident because, given how fast he was going and how much alcohol he had consumed, he was simply not able to prevent his car from hitting the child. Even if we agree with this driver about the facts, we won't agree with him about his moral responsibility. He could have avoided the accident earlier: by drinking less, by taking a taxi instead of driving himself, or by driving more slowly. Similarly for racist (and analogous) emotional reactions: even if they are unavoidable at the time they are experienced, they may well have been avoidable earlier and are then morally attributable to the person.
If you assume that the air might really be cold, and the car might really be green, then I can think of two situations in which it is more appropriate to say "I feel cold" and "The car seems to be green":
1. You have doubts about whether the temperature really is low (perhaps you are getting sick),or whether the car really is green (perhaps the light is especially low). Conversely, you may want to assert that "It is cold" even though you do not feel it (perhaps because you just emerged from a hot bath) and "the car is green" even though you see it as blue (perhaps because you are colorblind).
2. You want to sound tentative or accommodating of other views (even though you may be quite confident of your own judgment). It may be more polite or friendly to say "I feel cold" or "It looks green" when others disagree.
I suspect, though, that your concern arises from the conviction that properties like coldness and greenness do not exist independently of a subject who feels cold or sees green. If you think that these properties are relational properties -- the result of a particular interaction between a subject and an object -- then it is still quite appropriate to report that "it is cold" or "the car is green", with the understanding that these are relational properties of the air and the car. (This is no different that saying "She is short", with the understanding that she is short in relation to some others.)
If, however, you think that coldness and greenness are properties that belong to subjects only, and that we mistakenly project them onto external objects -- that coldness is a feeling that we wrongly attribute to the air, and that greenness is a sensation that we wrongly attach to cars, then it would be more accurate to say that "I have a cold feeing" and "I have a green experience". The problem with this position is the problem of identifying feelings or experiences independently of the external situations to which they respond. How do we know what a cold feeling except through its correlation with actually low temperatures? How do we know what a green experience is except through its correlation with particular lights and surfaces?
There are two different, but related, issues here, on neither of which is there universal agreement among philosophers (but, then again, is there ever?).
First, there's "Molyneux's problem": Can a person born blind who later gains sight distinguish a cube from a sphere merely by sight (assuming the person could distinguish between them by touch)? There's some empirical evidence that the answer is "no". The psychologist Richard Gregory has investigated this.
But closer to your specific question is the philosopher Frank Jackson's thought experiment about "Mary", a color scientist who lives in a completely black-and-white world but who is the world's foremost expert on color perception. She has never experienced red. Would she learn anything if she experienced it for the first time? I.e., is there anything "phenomenal" to the experience of red over and above what physics can tell us? Jackson originally argued that there was, i.e., that Mary would learn something from the experience of red, namely, what it's like to see red, but he has recently changed his mind. The novelist David Lodge has explored the Mary story in his novel Thinks....
For more on Jackson's thought experiment, see the anthology edited by Peter Ludlow, Y. Nagasawa, and D. Stoljar, There's Something about Mary (MIT Press, 2004).
The fact is that the correspondence between colour and frequency is rough and approximate. To some "colours" (and what does this mean?) there corresponds no wavelength, or no single wavelength, of monochromatic light. Examples are the browns, the appropriately named "non-spectral" purples, and white. (Black is also an example!) The colours form a circle (roughly) or a three-dimensional solid of which the circle is a cross-section at middle brightness in fixed illumination. This is colour space; and the frequency scale does not really model its overal complexity, except around the one corner at the edge: the spectrum. This is related to the fact that there are three types of cone which respond to coloured light, not four. There is no photoreceptor which peaks in the yellow, so when we see yellow it is the "red" and "green" cones that are being stimulated. Scientists tend to draw the conclusion that "colour is a sensation", as Maxwell put it. But this can't be right, as I see it, for the most part for the reasons given in Thomas Reid's philosophy of sensation and perception. The relation between colour and frequncy or wavelength has been an issue since the wave theory of light was introduced by Thomas Young, but the problem was there for Newton even though he held a corpuscular theory of light; the big particles stirred up red or "red" sensations (_n.b._ red sensations), and the little ones blue ones, but the "Rays" (paths?) made of these corpuscles were "strictly" not coloured.
I think the best place to begin is with the first sentence: "All the empirical objects that I perceive around me are structures of sensations." I think this confuses two things. The objects we perceive are things like tables, chairs, tin nickels and left-handed paper-hangers. And none of those things are structures of sensations. Now it may be that the way we perceive these things is by having various sensations, and it's also true that in some sense the sensations are manufactured in the brain, brought about with the causal assistance of the paper-hangers and such. But the machinery of perception isn't the same as what's perceived.
More generally, it's no surprise that we perceive things by way of stuff going on in our brains. But that stuff isn't what we see; it's what makes seeing possible.
So yes: the real world really is real (last time I checked). It's not composed of sensations, though sensations may be among the many things that make up the world entire.
There are real cars, with real sizes -- five feet high, twelve feet long, for example -- and they would be these sizes even if there was no observer to notice them. When a real car appears to an observer to be smaller, or larger, than it actually is, we can speak of its apparent size as opposed to its actual size; but the notion of an apparent size only makes sense in relation to an observer to whom the car appears to be one size rather than another. That is why Prof. Moore considers the real size of a car to be an intrinsic property while the apparent size of a car is a relational property.
The distance between a car and an observer does not translate into a difference in the apparent size of that car to that observer since a distant car may appear to be its real size to some observers, and a nearby car may appear to be bigger or smaller than its real size to some observers. Thus, there is no general answer to your question about what distance a car must be in order for us to see its real size. Some people, in some circumstances, are very good at seeing the real size of a car at a distance; others are not.
Finally, it is important to remember that there is no such thing as an apparent car. If someone seems to see a car of a certain size when there is in fact none to be seen, that is a fact about the observer -- not an intrinsic fact about a non-existent car nor a fact about a relation that exists between an observer and a non-existent car. The temptation to reify 'apparent objects' is partly responsible for the sort of confusions that you express in your question.
The surface grammar of the sentence “It’s hot in here” suggests that the sentence is about an objective state of the room. Let’s start there. There are two features of the assertion of this sentence that make you think it might not be about the temperature of the room: first, the assertion is based on a subjective experience of mine, and second, it uses the vague term “hot”. Let’s start with the first consideration. Notice that any claim anyone makes about contingent states of the external world is, if it’s a justified claim, going to be based on that person’s sensory experiences. If I say “You forgot to turn off the burner on the stove,” my claim will probably be based on seeing the flame, but my statement is a statement about the burner, not about my visual experience. Or if I say, “Something’s burning,” it’s probably because I smell the scorched butter, but it’s still the butter I’m talking about. (Guess what I did this morning making breakfast.) Contrast these cases with cases where I really do mean to talk about my sensory experiences: “It looked as if the burner was still on from where I was sitting,” “I smelled something that smelled just like butter burning.” In your case, the contrast would be between my saying: “It’s hot in here. (So turn on the air conditioning.)” with my saying: “I feel so hot all of a sudden. (I must be having a hot flash.) The first claim is a claim about the temperature in the room, and can be corrected, if it’s false, by someone else: “No, it’s not; it just feels that way to you because you’ve been sitting in an overly air-conditioned car.” The second claim is a claim about my subjective experience, and no one else is in a position to correct me about that. You say that we are “only perceiving” the heat in the room, and not taking any kind of “empirical index.” But in fact, “taking an empirical index” is exactly what perception is. (And I really like that phrase!) Our eyes, ears, nose, tongue, and skin are highly sensitive registers of specific physical magnitudes. The “brute” information about these magnitudes is then processed by specialized neurological systems into representations of the external world, which we can access consciously and report on. Now think about what’s going on when I report, on the basis of looking at a thermometer, that the room is 85 degrees. The thermometer is functioning just like my skin does, reacting in a regular, law-governed way to changes in the ambient temperature. And in reading the thermometer and reporting on it, I am acting just like my own sub-personal (or unconscious) information-processing systems in accessing and reporting on the information delivered by my sense receptors. There is this difference between the two cases – a difference that might contribute to your thinking of the thermometer reading as “more objective” than the report based on the way the room feels to me: in the case where I read the thermometer, my evidence is publicly available, whereas in the case where I base my claim on the way the room feels, my evidence is available only to me. But that difference doesn’t affect the objectivity of the claim made – in both cases, I claim something about the room. Now: what about “hot”? There are two things that you might be picking up on here. The first is that “hot” is an imprecise term. That means that the content of my claim is somewhat indeterminate: how hot does a room have to be to count as hot? Where is the boundary between hotness, and mere warmth? Insofar as it seems to be up to me to fix the answers to these questions, the truth or falsity of the claim appears to be up to me. After all, you and I could differ on what counts as “hot.” (Think about the silly chili pepper symbols they put next to foods in some Mexican or Indian restaurants. They tell you that a three-pepper dish is going to be hotter than a one-pepper dish, but how hot, in absolute terms, is a three-pepper dish?) This is a problem about calibration, or rather about about synchronizing your calibration system with mine. Having some kind of external register that we can both refer to – like a thermometer – can help with this problem, but it doesn’t eliminate it. It only helps if we take for granted that our perceptual experiences of the states of the external register are synchronized. (Think about worried parents trying to decide whether to call the pediatrician: “Does he look pale to you?” “Would you call that a ‘rash?’” “I wouldn’t say the vomiting was ‘projectile.’”) Furthermore, note that the “precision” of a thermometer is only relative – the marks on a thermometer have width, after all, and the level of the mercury might fall within the space of a single mark, rendering the reading “85 degrees” vague. Is it 85.1 degrees or 85.3 degrees? The thermometer at my house couldn’t tell you. But now the second thing about “hot” is that it’s an adjective that begs for a complement. There’s no such thing as “absolute hotness:” what’s hot for a room is not at all hot for an oven. So the claim that something is “hot” seems to need qualification; we need an answer to the question “hot” for what kind of thing? Terms that behave like “hot” are sometimes called “syncategorematic” – they are only meaningful “with a category,” only in the context of modifying something. But to say that they must be used in connection with some kind of thing is not to say that that thing has to be explicitly mentioned. If I say, “it’s hot in here” my listeners will probably figure out that I mean to say that it’s hot for an interior room. (Compare: I stick my head a little ways into the oven to check whether it’s working: “Whew! It’s hot in here.”) We human beings are (as the eminent psycholinguist Lila Gleitman says) are geniuses at pragmatics – at figuring out pretty complex thoughts on the basis of very stripped down verbal expressions. Sometimes we don’t have all the information we need to interpret what a speaker is trying to convey on the basis of what they say: if someone in another room shouts: “It’s way too cold!” I might not be to tell that she’s talking about her coffee, which is only 85 degrees, or the room, which is 72. But often enough, a shared context, or shared knowledge of the speaker’s context, can solve the problem of finding the presumed comparison. Bottom line: there’s no reason to think that the surface grammar of your sentence is misleading. The statement “it’s hot in here” is a statement about the room.