Legal certainty decreases over time. Rules and principles of law become more and more uncertain in content and in application because legal systems are biased in favor of unravelling those rules and principles. In this article I attempt to show what these biases are, and why commentators who have argued that the law tends toward certainty are wrong, then describe various attempts which have been made at restoring certainty, and why these attempts have generally not worked. My conclusion is that these proposals are at best holding actions, and that the tendency toward increasing uncertainty in the law is inexorable.