In order to explain how it is possible for a dharma to remain the same and yet also undergo change as it moves through the three times, the Vaibhāṣika held that dharmas have a constant essence ("svabhāva") which persists through the three times. The term was also identified as a unique mark or own characteristic ("svalaksana") that differentiated a dharma and remained unchangeable throughout its existence. According to Vaibhāṣikas, "svabhavas" are those things that exist substantially ("dravyasat") as opposed to those things which are made up of aggregations of dharmas and thus only have a nominal existence ("prajñaptisat").