We aren’t debating, or discoursing. We can’t debate or discourse until we’re not lying. Until we’re not lying we’re in conflict. So I am prosecuting your ideas to ensure you’re not lying. Only after you’re no longer lying, can we say that we are negotiating an exchange.
But if we start from your premise of lying, and your premise of falsehoods, an honest exchange is not possible. If an honest exchange is not possible, then violence is preferable.
So I am not trying to discover the truth. The truth is unknowable. I am not trying to discover an optimum solution, because it may be unknowable. I am only trying to ensure that you are not engaging in error, bias, wishful thinking, and deception.
At that point, what remains is but truth. And all truthful exchanges of mutual benefit are ‘true’ and ‘optimum’. And all lies and thefts by lie are neither true nor optimum.
So you start from the position of maximizing benefit. I start from the position of needing a reason not to kill you for lying.
(PS: If you combine ethical propertarianism with personal stoicism you are probably the very best thinker that man can be.)