Originally Posted by BobVigneault

I don't understand why he believes circular reasoning is a bad thing or something that can be avoided. He is working from presuppositions just as you are, are his presuppositions more coherent and sufficient for explaining his conclusions drawn from the same evidence.

Does he believe in 'belief'? For example, how does he solve the problem of 'other minds'? That is, he knows he has a mind because he can reason that out but how can he be assured that the rest of the world are not automatons. Can he prove with logic that we are not or does he assume and just believe that others are not robots?

How does he prove with certainty that the future will follow the same rules of the past. Gravity exists today but can he prove it will continue tomorrow? If not then he simply believes based on the evidence and in concert with his presupposition.

All reasoning is circular. This fellow is arguing from subjective assertions. Christians argue based on historical evidence and the presupposition that God has given us logic and reason to draw conclusions that form real and true Truth.

Where did this logic come from that he is using to attempt to knock down your argument? Is it the result of chance, a random burp of collective consciousness? He must justify the tools (knowledge and logic) that he is using to argue with you. Where is his justification?

Originally Posted by puritan lad

I would follow in the footsteps of Greg Bahnsen. Ask him how he can account for the laws of logic in a meterialist worldview. How can any law of logic or reason hold any significance beyond the brain cells that created them? If he uses logic to prove the laws of logic, he is involved in circular reasoning. If he uses any other method to prove the laws of logic, he is being illogical.

It is the mind of God that is the source for logic.