Logic is not just good, neat or nifty, it’s essential for surviving and thriving. Logic is one of the most powerful tools humanity has ever discovered. Yay for logic. But a retreat to pure reason is a retreat into fantasy. Deductively valid proofs evince logical consistency, and logical consistency only. A proof whose soundness is unknown, or assumed, (or presupposed), has no more utility than divination via the reading of tea leaves.
Dungeons and Dragons is a logically consistent system, too.