 Rational Monotonicity says that so long as new evidence \(\gamma\) is logically compatible with your prior beliefs \(C(\alpha)\), you should not retract any beliefs from \(C(\alpha)\). Accepting both Rational Monotonicity and Conditionalization amounts to saying that when confronted with new evidence that is logically consistent with her beliefs, a rational agent responds by simply forming the deductive closure of her existing beliefs with the new evidence. On that view, deductive logic is the only necessary guide to reasoning, so long as you do not run into contradiction. Stalnaker (1994) gives the following well-known purported counterexample to Rational Monotonicity. 