²⁸For example, Williams (2008b, p. 94) describes the Yogācāra viewpoint by Vasubandhu as “Apparently external objects are constituted by consciousness and do not exist apart from it. (...) There is only a flow of perceptions.” Claiming that the world does not really exist is a form of ontological idealism, while claiming that we cannot possibly know for sure if the world exists is epistemological idealism (Guyer and Horstmann, 2018). In Mahayana Buddhist philosophy and, especially, its Western commentary, there has been a lot of debate on which form to support. For example, Lusthaus (2013) warns about misunderstanding the Yogācāra literature to consistute an ontological statement while it is actually intended to be epistemological only. (For my part, I’m not committing to any such philosophical viewpoint here.) Even in early Buddhist texts you find claims related to such idealism: “And what, bhikkhus, is the all? The eye and forms, the ear and sounds, the nose and odours, the tongue and tastes, the body and tactile objects, the mind and mental phenomena. This is called the all.” (Samyutta Nikaya 35.23). However, this formulation open to interpretation and may also be seen as admitting the (ontological) existence of outside objects.