Chapter XXVII

Psycho-physic law, 17, 24, 46, 59, 66, 67

Pugnacity, 406

PURKINJE, 75

Pyramids, 85

Quality, 13, 23, 25, 56

Raehlmann, 349

Rationality, 173

Reaction-time, 120 ff.

Real magnitude, determined by æsthetic and practical interests, 344

Real space, 337

Reason, 254

Reasoning,