With the four ordinary preliminary practices or the Hinayana Buddhist view, we can conclude that all compounded things are impermanent, suffering and contaminated. They are called “contaminated” since various afflictions can be produced. The investigative method of the Madhyamaka teaches us to investigate this life and the next life, as well as various other external phenomena.  The Fundamental Wisdom of the Middle Way by Nagarjuna has twenty-seven chapters, and most of the content is an investigation of external substance, so as to understand that all phenomena are empty and to discover that the world is fundamentally an illusion that does not exist at all. Our greed and ignorance are thus undermined and will not develop.

~ Luminous Wisdom Book Series 9: The Principles of Liberation