Let's say we have the following statement to serve as a starting point around which a debate can be centerd.
Man is immortal
Someone could say that man is mortal according to accepted scientific fact but that isn't actually an argument in itself.
A supportive argument playing on interpretation might be to say that man can be immortal through his works and influence.
One disconfirming argument might be to say that man is not immortal because of aging and in turn it should be proven that advanced aging can have mortal consequences.
So how can one check the validity of these arguments and any examples you might be able to come up with?