  Beginning with Praśastapāda (6th century C.E.), the early Vaiśeṣika authors took a rational and scientific interest in the behaviour of projectiles and other moving bodies. Their theory bears comparison with Philoponus’ “impetus” theory, which was responsible for a paradigm shift in Western scientific thought. The Manual’s account substantially agrees with that already found in Praśastapāda, which is partially traceable to the Vaiseṣika-sūtra itself. The content of the relevant stanzas can be summarized as follows: