When? This isnt personal.
My contention is: soliphism and immaterialism and other brands of unreason are counterproductive and too uncommitted for my pallette. Its like a new emergent theism. Dismantling the truth. Undermining morality. Hindering ethical progress. Falsely equivocating rational scepticism and faith without evidence - these two things are worlds apart.
As a Nihilist, and someone who is leaning towards Solipsism I think you are incredibly ignorant of the last 5 millennia of philosophical thought dealing with epistemology.
In any case Edmund Gettier, proposed a thought experiment for this, Smith and Jones, who are awaiting the results of their applications for the same job. Each man has ten coins in his pocket. Smith has excellent reasons to believe that Jones will get the job and, furthermore, knows that Jones has ten coins in his pocket (he recently counted them). From this Smith infers, "the man who will get the job has ten coins in his pocket." However, Smith is unaware that he also has ten coins in his own pocket. Furthermore, Smith, not Jones, is going to get the job. While Smith has strong evidence to believe that Jones will get the job, he is wrong. Smith has a justified true belief that a man with ten coins in his pocket will get the job; however, according to Gettier, Smith does not know that a man with ten coins in his pocket will get the job, because Smith's belief is "...true by virtue of the number of coins in Jones's pocket, while Smith does not know how many coins are in Smith's pocket, and bases his belief...on a count of the coins in Jones's pocket, whom he falsely believes to be the man who will get the job."
These cases fail to be knowledge because the subject's belief is justified, but only happens to be true by virtue of luck. In other words, he made the correct choice (in this case predicting an outcome) for the wrong reasons.
René Descartes, prominent philosopher and supporter of internalism wrote that, since the only method by which we perceive the external world is through our senses, and that, since the senses are not infallible, we should not consider our concept of knowledge to be infallible. The only way to find anything that could be described as "infallibly true," he advocates, would be to pretend that an omnipotent, deceitful being is tampering with one's perception of the universe, and that the logical thing to do is to question anything that involves the senses. "Cogito ergo sum" (I think, therefore I am) is commonly associated with Descartes' theory, because he postulated that the only thing that he could not logically bring himself to doubt is his own existence: "I do not exist" is a contradiction in terms; the act of saying that one does not exist assumes that someone must be making the statement in the first place.
Here I will sum it up for you, like I did 7 months ago:
I think, therefore I am. So anything outside my thoughts I cannot prove. All other 'humans' could just be a product of my imagination created by an evil genius, I've constructed a 'reality' on false perceptions/data which was (unknown to me) embedded into my mind by the evil genius.Now I don't have a reason to advocate this, since it is pointless, since I know none of you really exist.