Editorial note — Page 368 CHAPTER XIV

[Footnote 1: James: Psychology, vol. II, p. 343.]

[Footnote 2: Ibid., p. 329.]

[Footnote 1: James gives an illuminating passage on the importance of the effectiveness of reasoning things out: "I have a student's lamp, of which the flame vibrates most unpleasantly unless the collar which bears the chimney be raised about a sixteenth of an inch. I learned the remedy after much torment by accident, and now always keep the collar up with a small wedge. But my procedure is a mere association of two totals, diseased object and remedy. One learned in pneumatics could have named the cause of the disease, and thence inferred the remedy immediately. By many measurements of triangles, one might find their area always equal to their height multiplied by half their base, and one might formulate an empirical law to that effect. But a reasoner saves himself all this trouble, by seeing that it is the essence (pro hac vice) of a triangle to be the half of a parallelogram whose area is the height into the entire base. To see this he must invent additional lines; and the geometer must often draw such to get at the essential properties he may require in a figure. The essence consists in some relation of the figure to the new lines, a relation not obvious at all until they are put in. The geometer's sagacity lies in the invention of the new lines." (Psychology, vol. II, pp. 339-40.)]