Yoga by Pathanjali is not what we commonly understand it is. Its a 'Being Human'. He asks us start slow, process slow, perfection can't be rushed, he totally agrees. He knows Carnots theorem :-) ! He is very unique in stating, 'you are your own master', do not look for a guru. His is an idea very scientific like this universe just existed, wasn't created. His words are like chaos theory - we were given a free will and our first existence, our every single actions, repercussions, changed the course of action, like a flutter of a butterfly changes the whole weather picture. Thus giving rise to various lifetimes with various possibilities for us get back to 'BEING-Human'. The one highlight is, he says, no amount of preaching would influence anybody, just live and show, people will understand and accept.