Patanjali is the sage traditionally credited with compiling the Yoga Sutras, the foundational text that systematized yoga as a philosophical and practical discipline. Scholars place the text somewhere between the 2nd century BCE and the 4th century CE, and little is known of Patanjali as a historical person. The name may represent a single author or a tradition of compilers. Among his lasting contributions are the yamas and niyamas, ten ethical observances that form the foundation of yogic practice before any posture or breathing technique.