I recognize two branches of science: Theoretical, whose purpose is simply and solely knowledge of God’s truth; and Practical, for the uses of life.
Practical Science, or the theory of the arts, is that science which is selected, arranged, and further investigated in details as a guide to the practice of an art.
The present writer will call […] science which differs from [heuretic science] in all the important respects which result from investigation being pursued, not because of the august nature of the truth sought, but for the sake of some anticipated utility of it to some man or men, practical science…
The third group of sciences consists of so much of the activity of building up edifices of knowledge as is motivated by a desire of ministering to a human want, whether this desire have or have not an ulterior purpose. The are what we call the practical sciences. Many of them go by the name of arts. By far the greater part of all scientific labor is bestowed upon these sciences.