Existence of human-kind

1 - Yes "you" the phenomena exists, and yes, "people" the phenomena exist to...now that in itself doesn't say much about what "you" are nor about what "we" are...

2 - Yes nothing is IMPOSSIBLE to exist in ANY way once nothing by definition cannot exist...a better form of exposing the trick in the language is to keep reminding yourself the tautology that nothing is nothing, therefore there is no nothing...

3 - Are you asking how can you be absolutely certain about what exists or whatever else ? You can't, but the criteria when lacking certainty rather should be if you have any GOOD REASON to think otherwise...I guess if a friend displays good or bad mood towards you, you tend to assume he is having feelings...in principle your experience in social context and no contradiction like it happens in dreams is good reason enough to assume some beliefs...

Hi May
To assume that the "people" you experience outside of your "self" are constructed by your dreams etc... postulates a more complex system than a real "reality".
The situation you are describing is called Laplace's demon.
That line of reasoning was disproven in 2008 by David Wolpert.
I am sure that either Fil or I could explain in greater detail if you are interested.

In short other people actually are people.

If the demon must be a part of the universe, but what if it isn't?
David Wolpert only proved no intellect can ever know it all. To what lies outside our universe, no one really knows?

I have not read the references cited above, but the fact that you are using language with which to think and communicate implies the "existence of others" from whom you acquired such language. Indeed some writers argue that your concept of "self" is dependent on such language as are all other concepts including "existence" itself. In short, solipsism is meaningless as it requires the social medium of language to even consider it.

Excellent. An example of how logic can be useful.

Not really. Fresco is just deriving from Wittgenstein's argument from language. Though a solipsist may admit there is inconsistency in using language but will follow up with, "What of that? A solipsist will argue that the reason that s/he is inconsistent because s/he was allow to be succumbed to the delusion of there being other beings and If s/he could resist the seduction of that delusion, s/he would use no language at all.

Whenever anyone asks this or a simiar question I wonder how they would react if they received an answer they truly believed and it was "No."

It seems something a psychotic would really enjoy learning.

....with whom and with what ?...and for what purpose?

And so it goes, just as the unstoppable force meets the immovable wall.

I for one talk and debate with myself a lot...in fact I would go as far as to say, that such a trait, self parlance, can be very helpful in preparing a solid argument...