Traits, mental, [310].
Trial and error, method of, [247].
Tropism, [245].
Utility, not the aim of science, [1], [4], [30], [38], [325];
nor the test of truth, [328];
but results of science are useful, [1] f., [4] f., [38], [331].
Value, not a scientific term, [1], [4], [22], [30], [325], [331].