All chaplains and leaders of Catholic Action should make a profound study of the marvelous tract of St. Thomas on Prudence. Prudence is essentially the virtue of action. With his keen psychology, St. Thomas analyzes the three acts which make up the exercise of prudence: to deliberate (the small inquiry, the interior counsel which one holds within himself); to judge; to act. Here we easily recognize practically the same three acts of the method of specialized Catholic Action: observe, judge, act.
– Abp Emile Guerry 1946
Emile Guerry, Prudence (Joseph Cardijn Digital Library)