can be acquired thereby are very old—­certainly older than Buddhism.  Such methods had at first only a slight philosophic substratum and were independent of Sankhya doctrines, though these, being a speculative elaboration of the same fundamental principles, naturally commended themselves to those who practised Yoga.  The two teachers of the Buddha, Alara and Uddaka, were Yogis, and held that beatitude or emancipation consisted in the attainment of certain trances.  Gotama, while regarding their doctrine as insufficient, did not reject their practices.

Our present Yoga Sutras are certainly much later than this date.  They are ascribed to one Patanjali identified by Hindu tradition with the author of the Mahabhashya who lived about 150 B.C.  Jacobi[658] however is of opinion that they are the work of an entirely different person who lived after the rise of the philosophy ascribed to Asanga sometimes called Yogacara.  Jacobi’s arguments seem to me suggestive rather than conclusive but, if they are confirmed, they lead to an interesting deduction.  There is some reason for thinking that Sankara’s doctrine of illusion was derived from the Buddhist Sunyavada.  If Patanjali’s sutras are posterior to Asanga, it also seems probable that the codification of the Yoga by the Brahmans was connected with the rise of the Yogacara among the Buddhists[659].

The Sutras describe themselves as an exposition of Yoga, which has here the meaning not of union with God, but rather of effort.  The opening aphorisms state that “Yoga is the suppression of the activities of the mind, for then the spectator abides in his own form:  at other times there is identity of form with the activities.”  This dark language means that the soul in its true nature is merely the spectator of the mind’s activity, consciousness being due, as in the Sankhya, to the union of the soul with the mind[660] which is its organ.  When the mind is active, the soul appears to experience various emotions, and it is only when the mind ceases to feel emotions and becomes calm in meditation, that the soul abides in its own true form.  The object of the Yoga, as of the Sankhya, is Kaivalya or isolation, in which the soul ceases to be united with the mind and is dissociated from all qualities (gunas) so that the shadow of the thinking principle no longer falls upon it.  This isolation is produced by performing certain exercises, physical as well as mental, and, as a prelude to final and complete emancipation, superhuman powers are acquired.  These two ideas, the efficacy of physical discipline and the acquisition of superhuman powers, have powerfully affected all schools of religious thought in India, including Buddhism.  They are not peculiar to the Yoga, but still it is in the Yoga Sutras that they find their most authoritative and methodical exposition.