The historical Buddha refused to answer many traditional ontological questions, or enter into many of the philosophical debates current at the time as they were distractions from the urgent task of saving beings from unnecessary further suffering. Soon after his time, Buddhists did begin to create more systematic philosophical treatments of Buddhist thought, but still always geared to liberation rather than philosophy for its own sake (somewhat similar to Marx’s opinion of previous philosophy, though Buddhist philosophy focuses more on changing ourselves rather than, or as a means to, changing the world). Traditional Indian philosophy does not show the same separation between ‘rational’ and ‘religious’ thinking that was made in post-Enlightenment Western philosophy. They can only be mentioned briefly here, but Theravada philosophy starts with the Abhidhamma (further teaching) section of the Pali Canon, and its method of breaking everything down into components (dhammas). There were several other non-Mahayana, non-Theravada philosophies taught by types of Buddhism that no longer exist (18? 30?), one of the most interesting being the ‘Personalist’ who taught that although there is no ‘self’, the notion of a ‘person’ is required to explain continuity and karma from one life to the next. One important Mahayana philosophy is Madhyamaka, originating with Nagarjuna and the Prajnaparamita ‘Perfect Wisdom’ texts. Its central teaching is that all things, even dharmas/dhammas, the skandhas making up a human being, Buddhas, or central Buddhist teachings like the Four Noble Truths are sunya ‘empty’. What they are empty of is ‘svabhava’ or ‘own being’, separate, independent, necessary existence. Another is Yogachara ‘teaching of yoga’ also known as Cittamatra ‘mind-only’ which teaches that what we think of as reality is a mental construct. It analysed human consciousness into several levels including one called the ‘store consciousness’ in which the seeds of karmic actions are stored from one life to the next. An Indian-origin philosophy, known better by its Chinese name Hua-yen or ‘flower garland’ teaches the ‘total interpenetration of all things’. What all Mahayana philosophies have in common is that whereas Theravada philosophy implies that we have to escape from samsara into nibbana, in Mahayana, nirvana is seeing samsara for what it really is.