But in probability theory, absence of evidence is always evidence of absence. If E is a binary event and P(H|E) > P(H), i.e., seeing E increases the probability of H, then P(H|¬E) < P(H), i.e., failure to observe E decreases the probability of H. The probability P(H) is a weighted mix of P(H|E) and P(H|¬E), and necessarily lies between the two.
