Here’s an interesting quote by William Walker Atkinson

“In order that the student may grasp the idea that I wish to convey regarding the use of suggestion as a means of exerting personal influence, I would have him understand that the mind has two general functions, which (following the terms used by me in my other writings) are known as the Active Function and the Passive Function, respectively.

The Active function does the voluntary, volitional thinking, and also manifests what we call “will power.” It is the function used frequently by the active, energetic, vigorous, wide-awake man, in his busy moments.

The Passive function does the instinctive, automatic, and involuntary thinking, exhibiting no “will power” and manifesting on entirely contrary lines from the Active function. The Passive function is a most valuable servant on man, and really performs the greater part of his mental work, doing all the drudgery and fulfilling its allotted task without receiving praise or thanks. It works uncomplainingly, and apparently without any effort, and never seems to tire.

The Active function, on the other hand, works only at the promptings of the will, and uses up a greater amount of nervous force than its Passive brother. It does the energetic active work of the mind, and tires after a great deal of effort and cries out for rest. You are conscious of, more or less, the effort when you employ the Active function, but not so when you use the easy going, faithful, good natured Passive function.

I think that you will understand the distinctive features of these two functions, from this brief explanation. Some persons do nearly all their thinking along Passive lines. Such persons find it too much of a task to do their own thinking, and prefer the “ready-made” thought of others, to that of their own production. They are practically human sheep. They are very credulous and will accept almost any statement made to them in an earnest, positive manner. These people are very suggestible and are practically at the mercy of those of a more active mind. They find it hard to say “No,” and are inclined to say, “Yes,” if it is easier and requires less thinking.

Others are not quite so suggestible, and some are scarcely suggestible at all, at times. But the latter, when they relax and give their Active functions a rest, are much more suggestible than at other times.

To enable you to form a mental picture of the two functions, for the purpose of carrying out the instructions given in this course, I will ask you to imagine a pair of twins who are associated as partners in a business enterprise. They look exactly alike, but have very different qualities, and each one is well fitted for the performance of the special duties, which he has undertaken. They share equally in the profits and losses of the business. The Passive brother attends to receiving goods; filling orders; packing goods; keeping the stick in order, etc., while the Active brother financiering; pushing things along, and, in short, is the executive of the concern and its active spirit.”

To understand exactly what Atkinson is talking here and how you can develop it, begin the training:
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