I recognise the differences between 'affect' and 'effect' as verbs, but I don't apprehend them while they are nouns. http://www.oxforddictionaries.com/definition/english/affect#affect-3:
[mass noun] Psychology Emotion or desire as influencing behaviour.
How does this differ from 'effect' as a noun? An 'effect' can truly be "influencing behaviour"? In this example
from Prof Christopher Day, why can't effect be used?
(Actually, affect is used many times on that page proper):
In Western thought, affect and emotion have been distrusted, denigrated, or at least set aside in favor of reason. The tendency to distrust—even deplore—emotion has been aggravated by the rise of professions with their insistence on detachment, distance, cool appraisal, and systematic procedures.