We can't 'prove' anything. First, after defining our terms, so that all involved are talking about the 'same' thing, we can get to the statement, notion profered. In a logical discussion and investigation into the 'truth' of this or that statement, we provide some 'evidence' for all to examine. While your interpretation of that evidence, at this moment, might seem like absolutely indisputable 'proof' of this or that, another person might examine the same pile of evidence and find it completely meaningless, or insufficient for further thought, and everything between.
So,
you can define your terms,
offer the evidence upon which your 'speculations/conclusions' are based,
and offer your thought processes in how you get there from here.
What goes on in the mind of the other person, once they understand you, is their business, with their own 'conclusions' to come to.
There is no 'proof'; those who demand it are demanding the impossible. Perhaps the above is what they actually mean by their ignorant demand?
The very demand for 'proof' is indication, perhaps, of the 'intellectual sophistication' of the 'demander', and at times, brings into question the fruitfulness of further discussion.

I don't think that all philosophical arguments require proof, but claims without merit do not stand for long without some reasoning or evidence backing them up. For example, if someone was to argue the aim of aliens here on earth, a major foundation for the discussion would be the fact that aliens interact with humans, and they have somehow found the planet earth.

I see philosophy as the process of making connections between ideas. What good does it do to make connections between ideas when the ideas may not even be valid to begin with?

Anything can be proven with enough assumptions, the question is whether you can convince people of enough assumptions to make a conclusion logically necessary. If you can do that then you have a proof. The proof is not that X must be true, but that if assumptions A1-An are true, then X follows logically. The trick is in the argument to allow for A1-An.

Speculative philosophy is fine, it makes no final assertions, but rather is a game of 'what if'. Proof can play into this in the form given above, but the assumptions are the speculations, so you say what if A1-An, well then X. A1-An do not need to be argued as they are given to be speculative.

The term "proof" is often used when the conclusion need not be logically necessary. That is a requirement in mathematics and logic, but not in the law, where "proof beyond a reasonable doubt" is the standard, or, "the preponderance of evidence". The first is the standard in criminal cases, and the second in civil cases. The reason for that is clearly that more is at stake in criminal cases than in civil cases. But neither of them requires that the conclusion be logically necessary on the basis of the premises. And, since in science, we have inductive, not deductive proofs, the standard you give would mean that in science there are no proofs at all. So the use of math and logic as the model of proof seems to me not a good one.

Of course, what we should require in philosophy is argument, so that what is asserted is supported. Even if what is asserted is true, why should it be accepted without argument? But all kinds of degrees of strength of argument should be used. Let the audience make the decision.

Offering proof for a philosophical system is like offering proof for a painting. If we need proof to philosophize, we're in trouble. What philosophy does need is logic, by which I mean coherence. I think the object of a philosopher should be to present a certain vision of reality, like a painting.

I think comparing philosophy to painting is appropriate. I think it was Santayana who argued that philosophy is art. If we look at those philosophers who have held up over time, their work is immensely artistic. Look at Nietzsche or Chuang Tzu. The art of philosophy spans all movements and schools of thought.

When you first come on the philosophy scene, say as an undergraduate, it seems like there's a method to philosophy, some substance, some established stuff and others needing to. The more you get into it, the more you realize that this is an illusion. There's no method to show the truth of anything in philosophy, and as a consequence, no truths ever established in philosophy. So in a sense all philosophy is "speculative." This is not a philosophical statement I'm making here--merely an empirical observation.

I'll elaborate. Take analytic philosophy and its "method" of argumentation for example. Ok, if you accept certain logical principles to be true (some dispute even those), and if such and such premises "entail" the conclusion, you've provided support for your conclusion. But why should anyone take those premises seriously? Where are THEIR support? Ok, so you come up with more arguments, this time for your premises. But then... you can quickly see that we get into an infinite regress requiring infinite further premises UNLESS we can stop somewhere with premises that don't require support--perhaps what some people mean by "self-evident" truths. Great. If we can get some self-evident truths then maybe we can finally establish some truths. But where are self-evident truths? And what makes them "self-evident"? Does it mean that everyone would agree with its truth upon simply hearing and understanding it? In that case, there would be no (or extremely few) self-evident truths as even logical principles (like principle of noncontradiction) have from time to time been denied as being true. In over 10 years of studying philosophy, I cannot recall a single proposition that was universally accepted or wasn't controversial.

Perhaps in the last 10 years or so that I've stopped studying philosophy, someone has actually come up with a method to show the truth of things. If so, all you have to do is point it out, show that there is such a method, by telling me what that method consists of and how it shows the truth of things. Afterall, I'm not making a "philsophical argument" here, merely pointing out an observation. Just show me the pink elephant and I'll believe you; there's no need to "argue."

But if you do accept that there's no method to show the truth of anything and thus no truths ever established in philosophy, don't you find it a sham, a fraud? What gets published is merely what's popular (for the readers/arbiters of the publication), not that they establish anything. Today's analytic philosophy likes to pretend it's substantive, that it's different from historical or "continental" philosophy, by insisting on defining terms, insisting on precision and clarity, etc. but that's all window dressing, that's just presentation. At core, there is no method, no way to get at the truths, only popular opinions. Today's analytic philosophy cannot tell you what right action is, for example, any more than Socrates can. At least he was honest enough to admit he knew nothing. How many today will admit that all those articles in all those journals and all those books are all merely speculative?

Though analytic philosophy at it's core is speculative, this is what makes it uniquely suited for the critical thinker, the critical thinker that does not wish to be shackled by a method, but rather decides to create his own. And while you may find this foolish, I find this beautiful; it's the pinnacle of the human mind, a field of opportunity with which one may frolic. It's thought in it's purest form, just a thought, without needing of substantiation, and this is what the human can best relate to. It's the meat of human interaction, a peek into the human condition, it's where I always find myself running back to with open arms. It doesn't necessarily have to make *sense*, be poetic, uplifting (often times isn't), or even coherent, but it's real. This is what I yearn for, because, in the end, this is all I have. And I ask, is speculation really a bad thing? For if we did not speculate, could we really come to any new truths, using any method? I think not. Imagination is what sets us free, it's the field with which truth can be found.

Don't misinterpret my intention: There is most definitely a problem with the illusion of substantiation. The lust to be "right", the fear of being "wrong", and the inability to grasp one could be neither. Oh, Khethil, we see the humans dividing camps again, no? Mixing wild speculation and knowledge derived from a defined method is like mixing water and oil, and Sleepy, you're right, the two should never be confused. Those claims that assume substantiation (by a popular method or otherwise) should be required of proof, without a doubt. But let us remember to remove the negative connotation associated with speculation in general, as speculation itself is not the problem but rather the validation we seek for our thoughts.

I think there is PLENTY of historically excellent philosophy that has not regarded demonstration of proof as necessary. A coherent argument that is built upon a reasonable person's understanding of the world is usually enough. In fact it's probably the minority of cases in which proof is offered.

Still you must admit, a bit of proof is nice.

"A reasonable person's understanding of the world" changes from century to century and even varies in the same century. During Descartes' time, dualism wasn't unreasonable. Today, dualism is almost universally condemned as unreasonable in analytic philosophy. Who's right? Was Descartes really unreasonable? And what of today's dualists? Are they unreasonable?

If popularity is what decides what's reasonable, then it has nothing to do with the truth for it changes all the time. But if we're to require universal agreement, then we must admit we have no philosophical knowledge at all as there's no universal agreement on anything. The problem is that no one's ever come up with any method to show the truth of anything. Everything's merely speculation. No philosophical proof is possible. What this or that philosopher comes up with isn't a method, only their view of the world, only speculation. You can debate, present arguments, etc. for the sake of acquiring agreement (if we happened to prescribe to the same premises), but truth? No. No one has a method to get at the truth. Agreement is sometimes possible, but knowledge? If it's possible, no one has gotten hold of it yet, at least not any they can SHOW to be knowledge.

I think it depends on how plausible or notorious something is.

There's a reason why arguing the existence of God for instance is classified under philosophy and not science.

Are you suggesting that science will never have an opinion on God? The evidence is against you. The logical analysis required for science leads one to question His existence, or to tighten up His definition, and I think it would be a mistake to throw this result away by placing a limit on what science can discuss. We might argue that atheism is not a valid or necessary result of science, but we can't disallow science from trying to reach such a result. I should have thought that a fundamental theory must have implications for God.

God is an algorhythm.

Some truths are self obvious and need not be proven (outside of their own systems, that is), for example, the laws of mathematics, the laws of non-contradiction, and so forth and so on.

You can't really prove anything. Our ideals are just what we believe are facts to the human eye, does it make them truely "facts"?

For me philosophy is inquiry.

If you are going to halt your inquiry for proof, you may never go very far. For me, say what you want. The most outlandish things are the most interesting. The majority are always in the middle. If you want to find some really interesting stuff, go to the edge, where the majority are to fearful to approach.

Good luck in your travels and inquiry!

Rich

Philosophising is different from offering opinions or from spreading propaganda or making a poem or preaching a doctrine; it is a proposing an account or explanation of the world. It is this distinction of the philosophical endeavor and the way it is communicated to Others that explains the necessity for providing warrants for their assent.

If we examine the origin of philosophical thinking, we find it in its gradual and difficult separation from poetical, mythological, and religious thinking and explanations, and in its demand for a different kind of answer to the basic questions of why and how and what.
Is not the whole point of philosophical thinking to supply warrants for its conclusions and perspectives, to appeal to the commonality of reason (in a rather broad sense) for consideration and understanding?