These lectures will reflect on metaphysical speculation in the history of Indian religions paying particular attention to the ways in which doing, or practice, connects with thinking, or philosophy, and how metaphysical concerns address problems of the relation of self to world, the nature and meaning of sacrifice, the category of the self in relation to person and transcendence, and the nature of language. Although the chronological span of these lectures will be wide, we will nevertheless focus on the early medieval (i.e., the post-Gupta) period for by this time the different schools were established and there is a history of discourse that we can examine. The implicit thesis of the lectures is that action, and in particular ritual action, is the backbone of tradition and that philosophical reflection emerges from the nature of humans as creatures who act. We will not simply present and assess arguments, but rather try to open out or enter into the world in which metaphysical thinking occurs through examining ritual and meditative literature as well as philosophical commentaries and independent works. Examples chosen will mostly be from the religions of Śiva and the Goddess but not exclusively so.