Sounds like someone forgot the Categorical Imperative and used someone else as a means instead of an end in themselves.
Two men in Russia were apparently arguing about Immanuel Kant's philosophy when one of them pulled out a gun:
A philosophical argument over views on Immanuel Kant descended into violent mayhem in southern Russia, leading to a man being shot several times.
The dispute occurred when two men waiting for a beer became involved in an increasingly fractious argument over the work of Kant – the author of canonical philosophical text Critique of Pure Reason – according to a police spokeswoman in Rostov-on-Don, the town where the argument broke out.
The row ended with one of the men producing an air gun and firing several rubber bullets at his opponent.
Fortunately the attacker's interlocutor survived.