The Intuitive Argument

1. I do not know that I am not a Matrix-world "coppertop" (or that I am not a brain in a vat).
2. If I do not know that I am not a Matrix-world "coppertop", then I do not know that I am now sitting in front of the computer/sitting in a lecture theatre, ...
Therefore:
3. I do not know that I am now sitting in front of the computer/sitting in a lecture theatre.

This is a valid argument which says if p then q, therefore q.
However, some valid arguments can be stupid (e.g. circular arguments). Valid arguments can have false premises and conclusion.

What matters is whether this is a sound argument which is a valid argument with true premises.

So...
Is the intuitive argument a sound argument?
I think so.

                                        (Taken from the University of Melbourne philosophy lecture - Dr Karen Jones)