Phaedrus
Socrates explains what is would take for a speech about a topic to proceed systematically.
What are the requirements? Why does Socrates think that his approach is more likely to reveal the truth than a haphazard approach? How does this discussion bear on Lowe's account of the nature of the metaphysical enterprise considered as an investigation into the nature of a mind-independent reality?
On page 52 of Scullys translation of the Phaedrus (265c-266b)