in willing not to do a thing that we find in willing to do it. This fact he regards as a good reason for the suspicion that in willing to do a thing the image of doing it comes as a natural consequence of the idea and not "as a necessary dynamic factor in the action."
(2) "We can will acts images of whose resident sensations are not obtainable." This position, he holds, is supported by the fact that we can perform many operations in less time than it takes to call up the imagery. For example, one can write a combined series of figures, letters, dots and dashes in less time than it takes to call up the various resident or remote images representing the various movements. To this, doubtless, the supporters of the image theory would reply that all such movements have been practiced until so completely habitual as no longer to require the presence of the imagery that functioned at the time the movements were learned.
(3) In many of our voluntary acts we will to do things so complex that it would take all of us several minutes to call up the imagery of the series of movements involved. For example, we can will to draw a polyhedron of 28,000 sides. This objection is apparently based upon the erroneous idea that such a complex act as the example given is a single act. To draw a polyhedron of 28,000 sides is clearly not a single act but a connected series of acts, from both psychological and physiological points of view; and therefore, if it calls for imagery at all, practical necessity would demand a series of images and not a highly complex image before beginning the drawing.
(4) "In trying to get any one to make a voluntary movement we rarely take means specially useful in calling up the images of resident or remote sensations, and often do take means specially to prevent their appearance."
(5) "If we insist on the image's effective presence we make voluntary action sharply discontinuous with involuntary action." (The Mental Antecedents of Voluntary Movements, Jour. of Phil., Psy., and Sci. Methods, Vol. 4, 1907. pp. 40-42.)
The experimental study by Ach, Ueber die Willenstätigkeit und das Denken (Göttigen, 1905,) is perhaps the most systematic investigation of this question thus far made. Ach's position, it will be observed, agrees in a measure with the position of Woodworth and Thorndike.
Previous studies of voluntary movement, Ach finds, have for the most part been confined to reaction-times and have, therefore, neglected the psychological processes involved. The analysis of these processes is the author's object. He used simple and complex reactions with the Hipp chronoscope as the recording instrument.
