The way to understand the Buddha’s teachings is to see that they are divided into either the three yanas, or the four philosophical tenets. For those who wish to know the view or the philosophy of Buddhism then the best way to learn it is to know the differences between the views of the four philosophical tenets. When the Buddha made these presentations of the different philosophical views, the point was to allow people to investigate with their own intelligence the various teachings and in that way to become very skilled in the different philosophical views and to be able to learn how to analyse things for oneself.
Therefore what Khenpo Tsultrim presents here is the path of reason, the presentation of the two truths by the different philosophical tenets which leads one from a common understanding of what is real to ever more subtle understandings which can eventually lead to that which is beyond the intellect.