Thompson, Sylvanus P., [375].

Thomson, [376], [380].

Thorndike, Edward L., [3], [8], [19], [78], [79], [91], [97], [98], [116], [125], [187], [189], [191], [192], [193], [194], [196], [203], [213].

Thought, and language, [218-21]; originality in, [56-57].

Tolstoy, [100], [360], [361], [449].

Tools, man only maker and user of, [15].

Tradition. See Custom.

Trial-and-error, learning, [7], [48], [52], [216]; reflection as mental, [49].

Trotter, [85], [90], [117], [107-68], [173], [434], [451].

Tufts, [417], [433].