Is thinking possible without language? If by language is meant oral speech and written words, the sign-language of deaf mutes is sufficient to compel an affirmative answer to the question. Moreover, there are modes of thinking and of expressing thought other than by the use of words. Of the means of expressing thought without words, symbols like the ten digits and the sigma of the new psychology are well-known examples. The player in a game of chess, croquet, or billiards thinks movements in advance of making them, and generally without describing the same in words. The drawings and plans by means of which the architect designs a new building, the mental images of mechanical contrivances which precede the invention and construction of machines, the mental pictures used in designing, engineering, and sketching, in original geological thought, prove beyond the shadow of a doubt that thinking may go forward without words and sentences, and may find expression in ways better adapted to the needs of the artisan. The graphic method of presenting to the eye the results of an investigation is less cumbersome than any description in words. Some men depend so much upon mental pictures in their thinking that they assert they cannot think at all without them. In some kinds of gymnastic drill the movement is described in words, then conceived by the mind, and finally executed. This exercise has a different educational value from the exercise in which the student simply imitates the movements of the teacher, the latter being an instance of thinking and expressing thought without the help of words. The speed with which many movements must be executed, as in fencing, legerdemain, athletic sports, the manipulation of the lever in the hands of the engineer, requires thinking without the intermediate agency of words and sentences. The time it takes for an idea to pass into words, and through them into actions, is measurably greater than the time required for the direct translation of thought into action. Although the difference in specific instances is measured by the fraction of a second, it would involve serious loss of time as well as energy in the handicrafts if thoughts could only pass into action through speech or written language.