What do you think of Voltaire’s quote?

“If you wish to converse with me, define your terms”

— Voltaire

My take is, yes, you should define the terms, it does help in the discussion. But it still doesn’t stop terms from being redefined in the middle of the discussion. Presumably, as discussion continues, in the long run, there should be sufficient consensus in the terms to both parties. However that is hardly in my case.