The Theravādins and other schools such as the Sautrāntikas attacked the realism of the Sarvāstivādins, especially their theory of time. A major figure in this argument was the scholar Vasubandhu, an ex-Sarvāstivādin, who critiqued the theory of all exists and argued for philosophical presentism in his comprehensive treatise, the Abhidharmakosa. This work is the major Abhidharma text used in Tibetan and East Asian Buddhism today. The Theravāda also holds that dharmas only exist in the present, and are thus also presentists. The Theravādin presentation of Abhidharma is also not as concerned with ontology as the Sarvāstivādin view, but is more of a phenomenology and hence the concept of svabhava for the Theravādins is more of a certain characteristic or dependent feature of a dharma, than any sort of essence or metaphysical grounding. According to Y Karunadasa: