The central drive to self-preservation, which in part determines my other appetites, strictly matches a universal and unchanging feature of individual physical things. My rational reflections have as their objects my first-order desires and the activity of thought is embodied in a corresponding activity in the brain. In reflection, forming ideas of ideas, I evaluate the desire, or other thought, positively or negatively, either affirm it or deny it, or suspend judgement on it. The reflection is an activity of the mind, its self-assertion, against the inputs from external things.
