Synopsis Vedanta has often been studied without relating it to the Vedic system of knowledge. The reason behind this situation is the fashionable but wrong view that Vedic thought is 'pre-scientific' and at best it represents' archaic modes of thought'. But recent scholarship has shown that astronomy was one of the bases of the design of Vedic fire altars and an astronomical code has been discovered in the organization of the Rgveda. It is now being accepted that the Vedic people knew considerable astronomy that included the knowledge of planet periods. Knowledge of astronomy and the concomitant sciences provides the backdrop in which the development of the science of 'self' can be understood. The Vedic system of knowledge is based on equivalences (bandhu-) between the cosmic, the terrestrial, and the physiological, this recursive system of knowledge was represented in terms of altar designs at one level and by the richly symbolic language of the Veda-s, where there is a constant allusion to the equivalences, at another level.