To the outside observer the history of Hindu sectarianism often appears as a disorganized tangle, lacking clarity and precision. The whole process is made if anything more complex by the ill-defined relationship of sect and non-sect. As Renou remarks: Though no statistics are available, even for the present day, we have grounds for supposing that the most active sects were themselves only isolated groups within the great body of believers. From another point of view, however, the history is more understandable. A considerable part of sectarian activity during the past 1,500 years has been concerned with the spread and regional development of a single great devotional movement. Seen from this position, the uniformity and theological coherence of the sects, whether they be called Vaiṣṇavite, Śaivite, or by some other name, is remarkable and often overrides the no less real disparities of doctrine or detail at another level. Again, in this process regional variations have arisen in no small measure as a result of the popular character of the writings of particular saints. Thus, for example, Basava or Purandara Dāsa hold pride of place in the Karnāṭka, the one Vīra Śaiva, the other Vaiṣṇava; in Mahārāṣṇra devotion has in no small part been moulded by the thought of Jāân Dev or Tukā Rām; in the Pañjāb by Nānak; and in the Hindī region by Kabīr Dās, Tulsī Dās, and Sūr Dās. Throughout north India the influences which lay behind the movement were largely, but by no means exclusively, Vaiṣṇavite; yet other streams contributed, Śaivite, Buddhist, Tāntrika, Yogī, etc.