The sceptic claims that knowledge is impossible to attain. In short account: summarise his reasons for making this claim and say whether you feel that we are bound to accept his reasons, and why.

Knowledge is impossible to attain. There are a number of reasons for making this claim, based upon definition of what knowledge is. A statement, or proposition, is only knowledge if three conditions are met. The proposer or agent making this proposition must believe it is true, they must be able to give evidence of its truth, and it must be true. The problem is attaining all three of these conditions for the proposition to be held as knowledge.

The sceptic would claim that meeting all three conditions is impossible for anyone to attain. 'The earth is flat' was held for centuries to be the received wisdom, or knowledge of the time. Even after Copernicus and Galileo, a vast number of people in Western Civilisation, at least, believed this proposition to be true. They had much convincing evidence to hand to 'prove' that it was true. Today it is thought that there is too much evidence against the proposition to make it true. Orbiting the Earth in a spaceship for one.

To be able to prove a proposition, the sceptic would ask for proof by sufficient propositions that in total would prove the initial proposition to hold. 'That cat is black' would depend upon other propositions to be proposed that would validate it as truth. 'It is a cat' would be one whilst 'It is black' may be another one. The problem is that the sceptic could ask for propositions that held for each of these propositions. This demand for supporting propositions would eventually infinitely regress until a proposition could not hold, either for lack of proof, lack of belief by the proposer, or the statement is evidently untrue. It could be argued, for instance, that there is no such colour as 'black' in nature. There has to be some terminating proposition. This has led to a dependence upon the senses and what is 'real'.

Is that cat black? My perception of the form of the object, (it is cat shaped), and its colour (black) may not be the same as everyone else's. The sceptic would suggest that my senses are not reliable. Another person may say that the object is a grey cat.

Another may say it is a cardboard cut-out! As any amateur magician can show, the senses can be deceived.

It could be argued that all illusions are well documented and known to be illusions. The sceptic would argue that there is always interpretation of what the senses are telling you. A 'mirage' is very 'real' to a thirsty man! This interpretation is something private to the perceiver - called private space. This leads to a three component view of the world.

In answer to this problem of perception and the senses it has been proposed that there is 'private space' between the perceiver, the perception of the object - the 'percept'. The public space is the space between the percept and the actual object. Realism always claims that there is a real world out there independent of our senses, but that this is in public space. However the sceptic can argue that if all our perceptions are private, then how can we say there is an independent, real world in public space? If virtual reality technology takes off, how are we to tell what is real and what is virtual?

It seems we are bound by the sceptic's reasons to not entirely accepting the evidence of other observers of the 'real' world to match with ours. For we are sensing or perceiving their evidence which in itself could be self-deluding. The truth of a proposition could devolve to a statistical qualification, an assent by the majority!

If we whole-heartedly accept the sceptic's arguments against the attainment of knowledge, what is left? If the goal of acquiring knowledge is taken away from man then what would be the result? Acquiring knowledge of the universe and its workings may be the only way humanity can overcome its problems. We may be bound to take the sceptic's arguments on board, but to accept them without question would be to eliminate a major strand of human endeavour.