‘If you reason in the right way, you will agree with me; if you don’t agree with me that, in itself, proves that you haven’t reasoned in the right way’.
That is the essence of ‘justifying’ an argument or belief on the basis that ‘reason’ supports it.
It is essentially a claim that there is an ‘absolute truth’ which is discoverable by adopting the correct ‘reasoning procedure’.
Invoking ‘reason’ to justify an argument or belief is like “banging on the table” (to borrow from Alf Ross’ observation about invoking ‘justice’ in support of an argument).
“There are many who say that reason is not the decisive factor, but that other imponderables must be considered. I believe that there can be nothing of value which is not in the last resort based on reason.” That, of course, was Adolf Hitler. But it starkly demonstrates the tendentious and delusional nature of invoking reason, which can be deployed to justify even the most hideous of ideologies.
The fact is, reason is a neutral faculty. Contrary to what Emmanuel Kant claimed, it tells us nothing “on its own account”. If reason and instinct were the only ‘faculties’ in the human brain, then it would be better for humanity if the capacity to reason could be expunged from the brain.
The worth of the human capacity to reason depends entirely on whether it is in bondage to our primitive instincts or in service to the neurological moral network in the human brain. Reason in bondage to our primitive instincts makes us nothing more than ‘civilised’ savages.
Only when reason is in service to the neurological moral network can we begin to discover our true moral purpose and our true cosmic destiny.