The meaning of this aphorism is that a slip of the foot, that is to say, attempting to succeed in some given enterprise and failing in doing so (or in other words, choosing to act but failing, for whatever reason) is not as bad as talking without thinking (a slip of the tongue), since the latter can bring unforeseen, hurtful, and unfortunate consequences: what is once said cannot be taken back, whereas action can always be resumed and made better.
