Full Idea
What is common to most of the main thinker of the Enlightenment is the view that virtue consists ultimately in knowledge.
Gist of Idea
Most Enlightenment thinkers believed that virtue consists ultimately in knowledge
Source
Isaiah Berlin (The Roots of Romanticism [1965], Ch.2)
Book Reference
Berlin,Isaiah: 'The Roots of Romanticism' [Pimlico 2000], p.25
A Reaction
I have always found this view (which seems to originate with Socrates) rather sympathetic. What is so frustrating about cheerful optimists who smoke cigarettes is not the weakness of will or strong desires, but their apparent failure of understanding.