A good, principled way to cut off political (or similar) discussion: “You’re not going to convince me; so we might as well talk about something else.” Reasonable people accept this because, as reasonable people they understand that conclusions cannot be forced — they can only be attained through thinking for oneself. Unreasonable people will refuse to accept this, or only “accept” it in the context of a snide comment. In so doing, they reveal something about themselves: That they don’t reach their own conclusions by reason. So, on this subject at least — who needs them?