 Whether something is “so” (rán 然)—that is, whether some term is correctly predicable of it—depends on “that which makes it so,” in effect the satisfaction conditions for the term. Things may be similar in some respects without fulfilling the satisfaction conditions for the same term. Linguistic expressions may be similar in structure while having dissimilar satisfaction conditions. Hence we must be cautious in using the techniques of disputation. Any guidance provided by similarities between things or parallels between expressions must always be checked against our know-how concerning the “reasons” (gù 故, the grounds or criteria) for using various expressions.