What are some of the arguments levelled against idealism throughout the history of philosophy? In particular, I’m thinking of Berkeley’s idealism (but any will do).
Are you taking a summer course in philosophy? It really seems like you’re trying to get someone to write one for you. Why don’t you just google “arguments against idealism AND philosophy” ?
GE Moore’s your man:
ditext.com/moore/refute.html
- fairly specifically against Berkelian idealism. He led the development of analytical and ‘common-sense’ philosophy away from the general wash of C19th Idealism.
You don’t need to read that article, because you can conduct the experiment by which the external world is proved for yourself. —Just stick up your hands, and declare it to be so!! As if it wasn’t common-sense that common-sense sometimes misses the point.
I, on the other hand, will read that article. Although, since it’s Moore, I’m anticipating being disappointed.
I think the best argument against Berkeley’s argument for idealism is a thermometer.
Moore’s hand argument is probably the worst I’ve ever seen. Srs.
He does his famous mt/mp shift, but leaves it unsubstantiated. He shows on a purely logical level you can technically invalidate the skeptics argument, but then goes on to admit you can’t actually do it.
quoting myself from another site:
[tab]the skeptic starts off with this argument:
P1. If I don’t know that I’m not dreaming, then I can’t know that an external reality exists (I have hands)
This means that to prove that the external world exists one has to first know that one’s experiences refer to the actual world, and aren’t instead created in the mind. If our body of evidence doesn’t eliminate not-P, then we can’t know P, because that would mean that our body of evidence warrants both P and not-P.
P2. I don’t know that I’m not dreaming.
Here the skeptic says that one can’t actually show that not-P is false…that is to say, one can’t show that it isn’t possible that I am dreaming all these experiences.
Conclusion:
I can’t know that an external reality exists.
But Moore, that sly devil, works up another argument which uses the same first premise, but then adopts another premise 2.
P1. If I don’t know that I’m not dreaming, then I can’t know that an external reality exists (I have hands)
P2*. I know that I have hands.
Here, instead of affirming the antecedent, he denies the consequent. The skeptic uses modus ponens to affirm the consequent of the first conditional, then validly draw it’s consequent in the conclusion. Moore uses modus tollens to deny the consequent, thereby allowing him to conclude that the antecedent of the first conditional is false, i.e. I do know that I’m not dreaming.[/tab]
He never argues or in any way justifies the claim that he KNOWS that he has hands. He assumes that he does in order to make the argument prototype work. Nothing really changes though. You’d still have to show that you know you have hands, and to do that you have to dismiss the possibility that you’re imagining everything.
Now here’s the kicker. In his essay On Certainty, he says this:
Of course reasons can be given. There’s nothing inherently impossible about that. You don’t have to give a proof that something is possible. You just need that it not be logically inconsistent. All logically consistent propositions are possible. RIGHT?! Earlier on in the same essay he had no problems admitting that it is logically possible that the evil demon argument is true, and now, for whatever reason he says that the same can’t be said of the dream argument. Dishonest asshole. Or, if you want to grant him honesty, then he’s a careless dumbass.
Everyone seems to be fap-happy about Moore’s simplistic common sense argument, because, well, the skeptic arguments are silly (matrix, brain in a vat, evil demon…COME ON, REALLY?!) and so an equally silly argument ought to be both sufficient and appropriate.
Nope.
Right! Let’s burn him! Oh wait, he’s dead already. 
I think I’m in agreement with Moore in a sort of Putnam manner - i.e. reality is whatever we perceive it to be - so my hands are real - i.e. the reality of the world is axiomatically confirmed in our experiences of it.
Anyway, the reason I’ve been obsessing over Berkeley (if ILP memebers haven’t noticed, this is not my only post on Berkeleian questions lately: viewtopic.php?f=1&t=176310
For the record, I was being sarcastic.
This response is typical of anyone who manages to completely miss the point.
cool story bro
Well, experiences are used to justify the reality of the world, but whether they’re enough is the question. Moore assumes that our experiences are enough, and goes on to simply say that if experience were enough to justify the belief that I have a hand (i.e., the world exists out there as I imagine it in my mind), then that knowledge would imply that it is not the case that I am fabricating reality. Well, no shit. The problem is showing that you have this knowledge. It’s no big philosophical point to say knowledge of the real world discounts the skeptics theory.
What do you mean “showing”? You mean like convincing others that when you say you see blue you really do see blue? Seeing the reality of the world in your experience is just like this I think. Whereas seeing the sky as blue is characteristic of one particular experience (and people can doubt your claims), seeing the world as real is characteristic of all experience (and people can doubt your claims on this front too). But I would just as well go ahead and assume their experiences of the world hit them as quintessentially real just as mine do; if they want to deny this, they’re either dishonest or don’t quite understand what I’m saying.
Geez, how long have you been on the internet? 
I think the sceptic’s argument is pretty shoddy evidence for idealism. It leaps from “P is not logically impossible” to “P is the case”, as if the fact you can’t prove something beyond all doubt is evidence for its falsity. At best, you can be no more certain that Idealism’s the case than you can be uncertain that you’re not dreaming. Which is harsh, considering the demands they make of realism.
Secondly, the whole “I don’t know I’m not dreaming” - it’s crap. Most people, given a moment to reflect, know that they’re not dreaming. Dreams often seem convincing because you don’t reflect, and once you do it’s not uncommon at all to realise you’re dreaming. And we all talk about dreaming and know what it is to talk about dreaming - you can wake from a dream and find you’ve fallen out of the bed you went to sleep in, and practically no-one dreams they got fired and then doesn’t go into work again because they were so convinced. We can watch other people (and animals) dreaming, have amusing conversations with them, or tie our dreams in with reports of what was going on around us.
Dreaming is not something that makes sense to talk about without the assumption of a daily waking reality to compare it with. Similarly if you want to reword it to hallucinating. Have you ever hallucinated? It’s disorientating, confusing - even if you don’t know you’re hallucinating, you’re not in a restful, ordered state of mind.
But it could be, it is logically possible, that we’re in some Matrix situation, and the reality we wake to is a more stable, consequential supercomputer simulation, or a dream in the mind of God. It could be. Or it could be that you take a look at your hands and are certain they’re your hands. Which strikes you as the philosophy to put more time into?
Take a look at your hands. If what you see are not your hands, what can you say you know?
The standard for knowledge is high, and it is with this standard in mind that the skeptic argues. They’re not concerned with validating the possibility that we’re all brains in a vat. Nobody really believes it. They only posit it as a possibility, and as a mere possibility it has some strong implications. It says that the body of evidence we get from experience warrants the BIV conclusion just as it warrants the theory that we’re experiencing external reality. I mean, we have our experiences, and we need a theory to explain them. Maybe our mind is a mirror for a reality that exists out there. Maybe reality out there is a mental projection. Both theories explain our experiences. The problem is they’re extremely mutually exclusive, as far as knowledge goes. One must not be warranted by the evidence in order for the other to be, strictly speaking, known.
The point is the brain is very capable of manufacturing a believable reality while we say we’re dreaming. You’re placing undue limits on the brain’s capacity to dream realistically. I’ve had self-conscious dreams before where I’ve wandered in the dream whether I was awake or asleep. I’ve wondered at times if I did something or if I merely dreamt that I did.
Again, knowledge…philosophy…higher standards. These philosophical problems are not real problems. They’re dilemmas, puzzles.
Not much. Then again I’m not missing much without knowledge. A justified and, for my purposes, functional belief is more than enough.
The latter option doesn’t strike me as philosophy at all. And about the former, I’m not aware of anyone arguing that a mere possibility in logical space would be proof or disproof of anything. Typically, Berkeley’s argument in a nutshell goes something like this: TRY to conceive it possible for an object to exist without the mind–i.e., unperceived (or unthought of). Berkeley thinks you will fail, always. --It is impossible to conceive of something existing outside the mind, because, while it is conceived, it is in the mind (being thought of). You might draw a conclusion that is something like: ‘Hence, one would not be so justified in making knowledge claims about the existence of a world outside of thought’. And if you were feeling bolder, you might want to slap the person in the face who thinks they can prove it with a thermometer—because they’re not even trying to do philosophy…which, since Socrates and Jesus before him, always involves questioning what everyone else takes for granted. Now, most people think Berkeley’s argument fails. Some don’t. But if we’re talking about which strikes you as the philosophy to put more time into… then I know what I choose.
I am a river to my people.
That’s right. DNA coding has us all as the same. The human machine is the same. It is the knowledge we have that develops permanence towards an identity in each and is valuable to each.
It’s where your knowledge directs you and takes you that can cause awkwardness among you and others in our individual minds.
And moreso when we’re not; I think you’re overestimating it immensely. How many times has your life changed based on an experience you had that you later found out you merely dreamed so realistically that you mistook it for reality? How many times has it happened to anyone you know? How many times have you even heard of it happening?
The point is, you have a vast corpus of experience to compare your dreams to, which is not in itself dream.
Then why even use the word knowledge? Hey presto, epistemology gone and these dilemmas and puzzles vanish with them. Meh, it’s medieval hyperrationalism at its most divorced from life and experience, and in the name of metaphysical truth and clarity at that.
Do you know your name? Do you know what language I’m addressing you in? Higher standards are well and good, and I’m a great fan of avoiding sloppiness of thought - but a certain height renders language devoid of any meaning whatsoever.
Of course, since I can’t even be justified in claiming I have hands, I certainly can’t claim to know what I’m talking about… and I leave it to your imagination as to how I typed my response. 
You may as well argue that “it’s impossible to read of something existing outside a book, because while you are reading it it exists in the book.” There’s no impossibility of anything existing in different ways in different senses.
Try thinking of an object without thinking of it - it’s (barely) one step up from “don’t think of blue elephants”. Knowledge come in the form of thought, argues the idealist (who’s at least partially wrong)* - and this means that knowledge must be only of thought? Rubbish. If I conceive a table existing, that conception exists in my mind, not the object conceived (which is, as I conceive it, a physical object while the mind is non-physical).
*Thinking is an episodic activity, knowledge is a disposition/capacity. I don’t know the capital of Germany only when asked, or several times a day.
Right. Existence is all that’s there and all that’s important. Not how it came to be in a state of existence … (but it does help if we share some patterned, predictable way of communicating what we know) … It’s all a matter of function, of utility. One uses the instrumentality of thought and knowledge. He is not the thought or the knowledge. He is separate and has no problem on his own. It is the knowledge and thoughts he is using to create experiences, tampering with the body and building up sensations. That’s where the problems are.
(1) I’m not sure what to make of this. Your analogy would be stronger if I couldn’t write what was in the book onto the wall.
(2) Yes, that’s the idea. Berkeley has this line somewhere that goes like, “what it amounts to is that we are eating and drinking ideas…” and then he goes on a shpiel about language, and then how whatever the oddities in ordinary talk, the common person will always talk on as before, so it doesn’t matter. The common person is a naive realist and the opposite of a philosopher—they’re someone who thinks that what seems unreflectively most obvious to them must thereby be a decisive argument for its truth.
Well, bravo! —That is indeed what we’re talking about. So, if you really feel like winning against Berkeley, you’ll have to do more than just declare that the object conceived is outside of whatever we mean by ‘mind’. Because, that seems to be just what Berkeley is denying. G.E. Moore has thrown his hands up—to prove an external world—and my beef with that is that it’s not even close to philosophical.
O_H:
At which point one can get on with some actual philosophising.
There are some things that you have to consider in the strictest court of inquiry that you would never even think to consider while you’re walking on the street, or in the laboratory. --That strictest court of inquiry just is a philosophy classroom. There, such arguments that amount to no more than, “Well, because it’s just freaking obvious to me!! Comeon guys, I mean, really! It’s just freaking obvious!!” are not very good at all. They even sound totally ignorant of the whole history and purpose of philosophy, from Socrates chatting about piety and justice, to Descartes by the fire with the wax, and Kant and his realms, to Nietzsche and his fictions, to, well, JohnJones and his animisms.
Faust, if you want to get back to some “actual philosophizing”, then go for it----I’ll just have no idea what the hell you’re doing.
I’ve already said the rest.