four Buddhist philosophical schools
The tenets propounded by the great Indian Buddhist masters and categorized by Tibetan Buddhist scholars into four main philosophical systems, each with a progressively subtle explanation of selflessness. The two Hinayana (Lesser Vehicle) schools are Vaibhashika (Great Exposition) and Sautrantika (Sutra), and the two Mahayana (Great Vehicle) schools are Cittamatra (Mind Only) and Madhyamaka (Middle Way).