 This passage seems to characterize knowing (zhī 知) quite narrowly, as the ability to recognize something encountered in perceptual experience. Elsewhere the Canons and Explanations use the word ‘know’ (zhī 知) with a broader scope, so that it includes cases other than perceptual knowledge, or at least other than knowledge of things the knower has personally experienced. One passage explains that though the senses are the source of perceptual knowledge, once we know something, we need not rely on the senses in order to continue to know it (B46). Our knowledge of something—that is, our ability to describe it—can remain even after we no longer perceive it. We can also come to know something by having it reported or explained to us without having perceived it ourselves (A80, B9). 