Note note 57 — ANALYSIS OF THE PHENOMENA OF THE HUMAN MIND James Mill

57 I cannot see any propriety in the expression that when we infer the sum of the three angles of a triangle to be twice a right angle, the operation consists in finding a second name which more distinctly points out the quantity than the first name. When we assent to the proof of this theorem, we do much more than obtain a new and more expressive name for a known fact; we learn a fact previously unknown. It is true that one result of our knowledge of this theorem is to give us a name for the sum of the three angles, “the marking power of which is perfectly known to us:” but it was not for want of knowing the marking power of the phrase “sum of the three angles of a triangle” that we did not know what that sum amounted to. We knew perfectly what the expression “sum of the three angles” was appointed to mark. What we have obtained, that we did not previously possess, is not a better mark for the same thing, but an additional fact to mark the fact which is marked by predicating of that sum, the phrase “twice a right angle.”—Ed.