I think "real" is very close in definition to "most-common". If one person sees a ghost, but 99 people do not see the ghost, then the ghost is declared to be unreal; despite the experience of the first person. However, what's real also seems to tempered by the idea of integrity. Even if a certain experience is common, discovering inconsistencies in the experience can also cause doubt. Neither commonality nor integrity is a foolproof way to know what truly exists, but those seem to be a large part of what society uses to define "real".

I think "real" is very close in definition to "most-common". If one person sees a ghost, but 99 people do not see the ghost, then the ghost is declared to be unreal; despite the experience of the first person. — Bird-Up

This is fallacious thinking. Suppose there's a group of people X, Y, and Z and X observes something, say W. The relevant probability for W being real - as in existing independently of X's mind and thus perceivable by both Y and Z, is 50%. The same probability applies to Y and Z i.e. both of their perceptions have a 50% chance of being real.

The probability that all of them, X, Y, and Z, are hallucinating i.e. W isn't real = 50% * 50% * 50% = 12.5%. Decidedly a lower probability that W isn't real than if only X observed W.

However,

The probability that all three of them, X, Y, and Z, are perceiving something real = 50% * 50% * 50% = 12.5%. As you can see, that all three, X, Y, and Z are observing W paradoxically reduces the probability of W being real.

Also, if my math is correct, the probability that X, Y, and Z are perceiving something not real = the probability that X, Y, and Z are perceiving something real = 12.5%. Having more observers didn't help.

a couple of preliminary comments:
1. Words have meaning in virtue of their negative space; running is not walking, or not flying or not stationary.
2. The same word can have different meanings according to their various different negative spaces. The engine running not stalled; the course is running next term; the rabbit is running not hopping.

real - not imaginary
real - not painted
real - not virtual
real - not made-up
real - not a hallucination
real - not a semblance

Thus a mirage is contrasted with an oasis or in optics, a real image with a virtual image. Don't expect there to be one single sense in which things are real; a stick insect is a real insect, but not a real stick.

This is fallacious thinking. Suppose there's a group of people X, Y, and Z and X observes something, say W. The relevant probability for W being real - as in existing independently of X's mind and thus perceivable by both Y and Z, is 50%. The same probability applies to Y and Z i.e. both of their perceptions have a 50% chance of being real.

The probability that all of them, X, Y, and Z, are hallucinating i.e. W isn't real = 50% * 50% * 50% = 12.5%. Decidedly a lower probability that W isn't real than if only X observed W.

The probability that three people are hallucinating the same thing is a lot lower than 12.5%.

However,

The probability that all three of them, X, Y, and Z, are perceiving something real = 50% * 50% * 50% = 12.5%. As you can see, that all three, X, Y, and Z are observing W paradoxically reduces the probability of W being real.


Also, if my math is correct, the probability that X, Y, and Z are perceiving something not real = the probability that X, Y, and Z are perceiving something real = 12.5%. Having more observers didn't help.

Depends on the situation. But usually, the more people that see something, the better the odds that it actually happened.

The probability that three people are hallucinating the same thing is a lot lower than 12.5%. — RogueAI

Show me the numbers.

Real is whatever that is not useful to humans as a concept or tool.

You really need specific numbers? Do you think multiple people hallucinating the same thing happens regularly? Or is it a very rare thing? When's the last time you had a hallucination? When's the last time you and two other people had the exact same hallucination?

I know this is like the largest question there is, but how did we even come up with the concept of "real?" — TiredThinker

Probably, the practical need for an invariant standard - measure (ratio) - lead to a 'speculative' search for a guarantee for all 'values' and 'limits' in every area of culture and endeavor. Later on, perhaps, a (conceptual? theoretical?) criterion for distinguishing between 'presence and absence' (and, more concretely, discerning facts from fictions) ...

The real is that which hurts you badly, often fatally, when you don't respect it, and is as unavoidable as it consists in whatever preceeds-resists-exceeds all (of our) rational categories and techniques of control (e.g. ambiguity, transfinitude, contingency, uncertainty, randomness). The real encompasses reason (Jaspers) and itself cannot be encompassed (Spinoza / Cantor) ... like 'the void within & by which all atoms swirl' (Epicurus). Thus, Rosset's principle of 'indispensible yet insufficient' reason (à la Zapffe, Camus, Meillassoux-Brassier).

For example (some attempts @ conceiving (or designating) the real):

https://thephilosophyforum.com/discussion/comment/351534 (A)

https://thephilosophyforum.com/discussion/comment/349320 (B)

https://thephilosophyforum.com/discussion/comment/429633 (C)

The real is that which hurts you badly, often fatally, when you don't respect it, and is as unavoidable as it is whatever preceeds-resists-exceeds all[ (of our) rational categories and techniques of control. — 180 Proof

Concrete stuff here, not abstract games. :up:

It's a bit of a classic misuse by philosophers, a textbook case for Austin.

Is it a real painting, or a reproduction? Is it a real coin, or a counterfeit? Is it a real lake, or a mirage? Is it real magic, or prestidigitation?

What is real is set by the item being discussed.

But philosophers will wander up the garden path by asking if it is real per se.

Last night I saw upon the stair
a little man who wasn't there...

Whole realms of verbiage built on the misuse of a word.

Reality at its most basic is our will and what happens apart from our will. I may want to fly with my mind alone, but no measure of trying will let me. I am able to type a response on the computer to you, so that is real as well. Reality is what we can, and cannot do.

You really need specific numbers? Do you think multiple people hallucinating the same thing happens regularly? Or is it a very rare thing? When's the last time you had a hallucination? When's the last time you and two other people had the exact same hallucination? — RogueAI

You said this:

The probability that three people are hallucinating the same thing is a lot lower than 12.5%. — RogueAI

You should've done some calculations.

I would not ask what is real, but what we call real.
We call real those referents that fulfill a series of conditions = something that is presented under certain conditions. For example:

To be perceived with a certain constancy.
To be perceived by more than one sense.
To be perceived by the greatest possible number of people.
To be perceived under certain circumstances of "clarity".

To present a certain degree of resistance to our physical and mental activity.

To be part of a real world, that is, a structure in which some parts are related to others on a regular basis. Interdependence.

We especially call real those objects that enter the scientific system within a certain level of consensus.

The object that fulfills these conditions we say is real, or that it is real with a more or less high probability.

Applying this type of criteria with more or less rigor we can reach the conclusion that we are before objects that are not real, even though they may appear to be so: a mirage, a hallucination, a dream, a fantastic or virtual image, an entity of reason, etc.

As we can see, these conditions refer to a semantic and epistemological field. We say that "we know" or "we believe".

I'd say anything that has the capacity/ability/power to affect the self directly or indirectly is real independently of it being perceivable (by the body or its sense of awareness-not everything that interacts with the self is perceivable).

Real is relative to what is not real. Now there's a revelation :smile:

That which has an effect/affect.

The relevant probability for W being real - as in existing independently of X's mind and thus perceivable by both Y and Z, is 50% — TheMadFool

Wait wait wait -- please tell me this is the probability because either it's real or it's not. Did I get it?

Really? What is the probability aliens will land on the WH lawn tomorrow? Isn't that really unlikely? Yes. Do you need me to do calculations for you on that? No.

Wait wait wait -- please tell me this is the probability because either it's real or it's not. Did I get it? — Srap Tasmaner

Yes, you got it. Anything wrong with it?

Really? What is the probability aliens will land on the WH lawn tomorrow? Isn't that really unlikely? Yes. Do you need me to do calculations for you on that? No. — RogueAI

Well, the fact of the matter is this: Given a group of people (X, Y, and, Z) making observations we've to assign a probability value for one person's observation being real/unreal.

What is the numerical value of the probability of one person's observation (call it P) being real/unreal. At this point we must realize that, supposing X is the one who makes the first observation, X doesn't, can't, know whether his observation is real OR unreal. What then is the value of P for X?

Remember that if P is less than 50% or more than 50% it implies either we already know that X's observation is less likely to be real/unreal or that X's observation is more likely to be real/unreal respectively. That's not true. If we had that information the very idea of having more observers would be pointless; after all, if P were anything other than 50%, a single person's observation wouldn't need to be corroborated with the help of other observers.

What follows from this I've already explained in my previous posts.

BTW, how do you know aliens landing on the WH lawn is unlikely?

When we say what is “real” what we are really saying is where must we draw the line between that which is possible/has the potential to exist and that which does not.

Many like to consider real as “material” but this negates the existence of forces and energy states and probabilities etc which have no matter or substance. Some like to consider real as “objectively observable” between multiple members of society but this negates an individuals internal experience Imagination and personality or uniqueness as it is not perceivable consistently by others, as well as important concepts such as morality, justice and ethics which you cannot scientifically prove or observe yet are understood collectively to varying degrees and augment scientific endeavour to make it humane.

Some believe “real” is that which exists consistently or with most certainty/ stability through time but that negates the passage of time itself which is inherently consistent but also the mode by which things change. It also means that the laws of physics are the most real while the painting I drew and then burned straight after was not real because it didn’t last long enough.

Some people also believe that what is “real” is that which is perceptible or has the ability to interact or pass information or be measured. In this case considering what is real or not is a mute point because we cannot concieve of nothingness. Nothingness or absence of something is a concept constructed by objects that exist using phenomena that exist and so is inherently biased. It is something that exists and contains information.

So my opinion is that everything is real and that time dictates what part of everything is real at any one stage. If we can generate simulations and also put our imagination into words images and media then I fail to see a limit on thought and the physical products of thoughts.

What is the probability aliens will land on the WH lawn tomorrow? — RogueAI

That ship has sailed, they're already in the WH.

Real is sometimes contrasted by fictional, illusory, or erroneous.
Other times, real versus not real is used like discovered versus invented.
Other times still, real just means exists.
Then there are some cases that overlap with objective/subjective.
All seems very contextual (and Englitch is my 2nd language).

(y)

Anything wrong with it? — TheMadFool

That it is wrong is a fact; it's a bizarre misapplication of the principle of indifference, but a mistake that looks like it's worth understanding. I'm going to think about it a bit.

That it is wrong is a fact; it's a bizarre misapplication of the principle of indifference, but a mistake that looks like it's worth understanding. I'm going to think about it a bit. — Srap Tasmaner

First things first. Consider that I'm observing something, say X. I don't know if X is real or not. What probability value should I assign to X being real?

..My options ----------------What it means
1. Greater than 50%.----It's likely that X is real
2. Less than 50%---------It's unlikely that X is real
3. 50%--------------------------I don't know. X is real is as equally likely as X is not

If I opt for 1 or 2, that means I know that it's more/less likely that X is real but then I'm contradicting myself because I began with not knowing whether X is real or not i.e. I admitted to not knowing whether it's more/less likely to be real.

3 is the correct choice. The probability for a single individual that what s/he's observing is real/not is exactly 50%.

I began with not knowing whether X is real or not i.e. I admitted to not knowing whether it's more/less likely to be real. — TheMadFool

What's before "i.e." there doesn't entail what's after. Why do you think it does?

3 is the correct choice. The probability for a single individual that what s/he's observing is real/not is exactly 50%. — TheMadFool

I believe all three options are incorrect, as this is a misapplication of what probability is. Probability is based on knowables. When you talk about the probability of a jack being pulled from a regular deck of 52 cards, we know that there are four jacks. Probability is making a prediction based off of the limitations of what we do, and do not know.

You cannot assign the probability of something being real, without first constructing some limitations. What does it mean to be real? What are the circumstances in which you observed something, and it was not real? Is there chance involved based on these limitations?

Until these things are answered, you cannot assign a probability. You are instead stuck in an unassessable uncertainty.

Please go to my thread :point: The More The Merrier Paradox

The faux statisticians here seem to have forgotten that Bayesian inference - if that it what they think they are doing - is about belief, not truth.

That's four times the answer has been presented, and ignored.