What's that, Holmes?

There are
one-story intellects,
two-story intellects, and three-story
intellects with skylights. All fact-collectors, who
have no aim beyond their facts, are one-story men. Two-story men
compare, reason, generalize, using the labors of the fact collectors as
well as their own. Three-story men idealize, imagine,
predict-their best illumination comes from
above, through the skylight.
~Oliver Wendell Holmes