Full Idea
What is called 'reason' is the passions enlightened, 'illuminated' by reflection and supported by a perspicacious deliberation that the emotions in their urgency normally excluded.
Gist of Idea
Reason is actually passions, guided by perspicacious reflection
Source
Robert C. Solomon (The Passions [1976], Intro.4)
Book Reference
Solomon,Robert C.: 'The Passions (1993 ed)' [Hackett 1993], p.15
A Reaction
To suggest that reason more or less is emotions strikes me as missing the point of 'perspicacious', which takes in facts outside our emotional world. We excitedly climb a cliff, then stop when we see the rocks are crumbling.