Considering the Third Foundation of Mindfulness as if it were a sheet of paper, and the First as a pen, then the Second as ink; the Fourth Foundation, mindfulness of mental phenomena, is what is written on the paper, creating our experience of being an enduring/autonomous self. During this talk, Peter reviews the categories of the Fourth Foundation of Mindfulness and the role they play in the development in the process of Awakening, dissolving one’s belief in an enduring/autonomous self. During subsequent talks, each of the categories within the Fourth Foundation will be reviewed individually as to their functions and how to work with them skillfully.