 No number of successful or failed tests will render the objective judgement true or false with theoretical certainty. However, Lewis thought the principle of inverse probabilities meant that the judgement can be highly probable with a few positive confirmations, even practically certain, in so far as the probability of \(P\) when \(S\) and \(A\) and \(E\) obtain may approach certainty as the improbability of \(E\) approaches certainty when \(S\) and \(A\) and not \(P\) obtain. The principle also explains why further tests may continue to increase our warranted assurance in the judgement even more, though not as dramatically as earlier tests increased our warrant (Lewis 1946, 190–92). Since confirming and gaining assurance that \(P\) gives us assurance in all the predictions that \(P\) entails about future experience (Lewis 1946, 239), the principle of inverse probabilities may explain how we can act on these predictions with increasing confidence. Even though experience of instances of \(S\) and \(A\) and \(E\) can confirm and increase the probability of one sensory conditional entailed by \(P\) independent of direct experiential confirmation of the other sensory conditionals entailed by \(P\), experiential confirmation of one conditional increases the probability of the others, and vice versa (Lewis 1946, 348, footnote 6). 