This is the oldest of all transfer theories (also known as the Faculty Theory) . This theory assumes that the mind of composed of so many independent faculties, e.g. memory, attention, imagination, reasoning and judgment. These faculties, according to this theory, are nothing but the “muscles of the mind” and like muscles of the body, can be strengthened or improved through exercise (practice and use). In this way, such properly strengthened or improved faculties later on function automatically in all the situations and areas in which they are involved. For example, if the memory of a person is strengthened or improved, to a great extent, through memorization of long and difficult passages, then it can prove useful in memorizing dates, names, formulae, figures and, in fact, anything and everything that involves memory. In the same way, propagators of the theory claim that reasoning and imaginative powers developed through the study of geometrical positions can be used in solving various problems in life which demand a good deal of reasoning and imagination.
Mental discipline as an educational doctrine and as the basis for transfer of training was first seriously challenged by William James. He wanted to see whether daily training in the memorization of a poetry of one author would affect the learning of poetry of another author. For this experiment he acted as a subject for himself. He memorized 158 lines from Victor Hugo’s Satyr in 131 5/6 minutes spread over eightdays. He then worked for about 20 minutes daily memorizing the entire book of Milton’s Paradise Lost (Book-I). This required 38 days. After this period of memory training, he returned to Satyr and memorized 158 additional lines. But now he could do so in 151 1/2 minutes as against 131 5/6 minutes in the first instance. William James therefore concluded that memory was not affected by training as claimed by the faculty theory.
The above findings of William James were later supported by psychologists like Dr. Sleight and Briggs and others. Thorndike and Woodworth and others through their independent studies were able to conclude that the idea of finding any large difference in general improvement of their mind or its faculties from one type of mental activity or subject of study to another is absurd. As a result of all such studies and conclusions drawn by these later-day psychologists, the theory of mental discipline or the faculty theory now-a-days stands almost rejected for explaining the mechanism of transfer of learning or training in one situation from other.