The SciencesThe Mechanism of ProgressA Theory of InventivenessBy R. S. Woodworth on April 30, 1910AdvertisementABOUT THE AUTHOR(S)Recent Articles by R. S. WoodworthThe Psycholoǵy of Liǵht—IIThe Psycholoǵy of Liǵht.—IThe White Man versus the Savage