 Time, hence, is dependent for its definition on motion (NSLP 7, 54). The continuous nature of motion is essential to guarantee the continuous nature of time (DT 12). Time needs to be continuous for it to measure continuous motion (NSLP 8, 58). The continuity of motion, in turn, is guaranteed by the continuity of the parts that constitute the moving thing (DT 17). Kilwardby argues that time and motion are exceptions to the rule according to which the parts of composite things must exist simultaneously; instead, he claims, that they are composite transient things, and the parts of time are successive (DT 7–9). Time has its being from the ordination of its parts into before and after (NSLP 8, 58). The instant (the now: nunc) is from the point of view of the substance which is always the same but different in the manner of its existence (DT 89). Time is the measure of continuous motion, and the instant is the measure of one of the moments of that continuous alteration (DT 94–95). For Kilwardby, celestial motion as measured by time is the standard for measuring all other motions (see Trifogli 2013; for other aspects of Kilwardby’s treatment of time, namely the connections to his contemporaries, see Porro 1996.)