How to prove the world is real, and one isn’t just hallucinating everything? [duplicate]

Question

I'm not asking whether other minds are real or not, I'm asking whether the whole shebang is "real".

Google Gemini says it's impossible to know/prove it, and basically says to "move on". The only sort of explanation it's given is that the outside world is "consistent" and "predictable" (by using science) but hallucinations can be consistent too.

For all I know I can be a computer program and even my entire body is not real. How do I prove the world is real, and I'm not just hallucinating everything?

Answer 1

Two options: this reality is really real, or it isn't.

If reality isn't real, you're probably not going to be able to prove it's not real any time soon, nor figure out the real nature of reality. You're stuck here, in this fake reality, and so the stuff you do here will have the consequences it would have as if it were real even if it isn't. If you cut off your hand, it hurts and you have no hand. If you jump off a building, you break your legs - it really hurts, and it's expensive, and the recovery time is long.

If reality is real, then... all the same stuff above applies. You've got consequences that you have to live with.

The best option, I think, is to not worry about certainty, live your life as if it were real, because the consequences for messing up suck either way, but allow yourself a tiny little corner of your brain to acknowledge, every now and then, the tiny probability that it's all fake.

Answer 2

It sounds like you're asking:

How do I know reality is real?

So, there are variety of scenarios that have been offered in philosophy that challenge the thinker to think about proof and reality. All of them center around how do you prove reality is real:

• The butterfly's dream
• Descartes' demon
• Brain in a vat
• Many worlds hypothesis
• The Matrix

This is a good introduction into some key philosophical terms that stem from asking some simple-sounding questions:

1. What is reality?
2. How do I know what is real?
3. How do I prove something is real?
4. What is evidence?

These are the sorts of questions that start one down the path of reading more complex philosophy! Let's just craft a simple response. By knowing the four definitions above and then being acquainted with some key ides, you can begin to answer the question for yourself.

Ontology

The study of reality and its substituents is called ontology. The starting position of many thinkers about how build up the picture of reality and figuring out which things are part of it is that of naive realism. As a thinker becomes more sophisticated they might find other models such as scientific realism or subjective idealism, and so on. In the West, educated society has largely moved towards philosophies that are grounded in naturalism and physicalism in the secular world though Christian theology is still a fundamentally powerful source of philosophical thinking. Modern Catholicism offers a good blend of both.

Epistemology

How do you know something is real? How do you know anything and what is knowledge? The classical tradition going back to the Socratics is that of justified, true belief. There are some technical problems arising from Gettier problems. Then there are sources. Robert Audi, for instance, offers consciousness, reason, testimony, perception, and memory. The technical language about deciding whether something exists has to do with terms like existential quantification and quantifier variance, but those tend to be ontological terms where as the actual justification or judgement (SEP) is rooted in philosophy in terms of argumentation theory.

Proof and Evidence

These two terms are highly interlinked. A proof is a method that uses evidence to justify a conclusion. This requires a theory of evidentialism. This will vary from thinker to thinker. For instance, it is quite typical for theologians to accept supernaturalism and the power of faith. Revelation features quite prominently in terms of evidence among some traditions. In the secular world, empirical evidence and rationality figure quite prominently in proof. A good place to start for informal reasoning is Toulmin's Uses of Argument for his method. Argument maps are another tool for organizing proof and evidence.

The Non-Answer to Your Question

What you accept as proof that reality is real will be up to you. There is no authority that can tell you what is right and wrong, though some ideas and techniques are more useful than others. That means you'll have to read through these sorts of materials and come to a decision about what you personally favor. Personally, I would appeal to James Halliday aka Anorak the All-Knowing:

And that was when I realized that... as terrifying and painful as reality can be, it's also... the only place that... you can get a decent meal. Because, reality... is real.

Answer 3

There can be no such proof, but allow me to make a very simple argument against it by asking the following question.

Suppose we are hallucinating this. If we are, then this assumes there must be a reality outside of this hallucination (for otherwise the concept of a hallucination doesn’t make sense). Now, would that reality also be a hallucination? And if so, would the reality outside of that hallucination also be a hallucination?

As you can see, one can keep doing this forever. But something, somewhere, must be real and not a hallucination. The most parsimonious answer is to assume that this reality is the one that’s real and that there is nothing else.

Answer 4

The only tangible proof of a hallucination would be technical recreation of a similar quality believable hallucination. In a couple of hundreds of years, people should have sufficient computing power to simulate all the electrical signals the human brain receives and create 'hallucinations' indistinguishable from our reality.

That would be reasonable proof that our World is most likely a computer simulator.

Answer 5

The question can answer itself depending on the definitions used.

Do you think there are fundamental differences between perceiving reality vs. hallucinating?

If so, do you think those differences are knowable? Are they accessible, to the perceiver?

If, by definition, there is no difference, or, there is a difference, but it is unknowable, then it follows that there would be no way to distinguish reality from hallucination.

If, by definition, there is some collection of properties distinguishing hallucination from real experience, and that difference is knowable, then one would need to check if their own experience did or did not meet those criteria.

In my opinion, this question can be investigated in a very logical way, in the sense that, it can proceed by necessary tautologies, without requiring any empirical knowledge.

Answer 6

It can't be proved that life is real since we don't know what is beyond death! I meant, what if we are just computers and know that only after our death? What if this life is only a dream and when we die, we are welcomed into reality?