This paper carries forward the discussion initiated by the publication in 1986 of “A Refutation of Middle Knowledge.” Answers are given to two objections that have been raised against the original argument. Next, an alternative argument by Robert Adams is discussed; this argument has the advantage of avoiding reliance on one of the most controversial premises of the original argument. Finally, a definition is given for “S brings it about that Y,” and this definition is used to construct a proof (...) of the “power entailment principle.”. (shrink)