Concept:
Sarvāstivāda was one of the most influential early Buddhist schools. The name itself is a compound of three Sanskrit words: *Sarva* + *Asti* + *Vada*. The philosophical core of this school lies in its unique ontological position regarding the existence of "dharmas" (phenomena) across time.
Step 1: Etymological breakdown of the school's name.
• Sarva: All Everything.
• Asti: Exists Is.
• Vada: Doctrine School of Thought.
Therefore, Sarvāstivāda means "The Doctrine that All Exists." But what does "All" refer to?
Step 2: Philosophical application to the concept of Time.
The "All" in Sarvāstivāda specifically refers to the three periods of time: the Past, the Present, and the Future. Unlike other Buddhist schools (like the Theravadins) who argued that only the present moment exists, the Sarvāstivādins maintained that the underlying essence of dharmas exists eternally through all three times. While the *function* of a dharma might only be active in the present, its *substance* (svabhava) exists in the past and will exist in the future. Thus, 'Sarva' in this context is a technical shorthand for the totality of the three temporal dimensions.