 The Buddhist schools used the characteristics of conditioned phenomena as a hermeneutic tool with which to reinterpret impermanence in terms of momentariness. The Sarvāstivāda-Vaibhāṣika proposed a fully-fledged doctrine of momentariness according to which all physical and mental phenomena are momentary. The Sarvāstivādins use the term “moment” (kṣaṇa) in a highly technical sense as the smallest, definite unit of time that cannot be subdivided, the length of which came to be equated with the duration of mental events as the briefest conceivable entities. There is no Sarvāstivādin consensus on the length of a moment, but the texts indicate figures between 0.13 and 13 milliseconds in modern terms (Gethin 1998, 221; von Rospatt 1995, 94–110). This usage presupposes an atomistic conception of time, for time is not reckoned indefinitely divisible. Indeed, the term kṣaṇa is often discussed in juxtaposition to the concepts of material atoms and syllables, which are likewise comprehended as indivisible.