For geometry, you know, is the gate of science, and the gate is so low and small that we can only enter it as a little child.
In: Stephen F. Gull, Anthony N. Lasenby and Chris J.L Doran, Imaginary Numbers Are Not Real — The Geometric Algebra of, Spacetime, Foundations of Physics USA, Volume 23, Number 9, September 1993, (p. 1175)