Locks and Keys
To summarise, we find it convenient and relevant to divide the human brain’s awareness and activity into three ‘minds’: the conscious (creative, logical, rational), the subconscious (emotion, behaviour), and the inner mind (which sends subtle messages to the conscious). Rabbi Avrohom Abulafia, famous thirteenth-century Kabbalist, writes that the inner mind is guarded by what he terms, “a revolving sword” – an allusion to the revolving sword placed at the entrance to the Garden of Eden (Genesis 3:24). Today, this is called the Conscious Critical Faculty, or the CCF.
This sword, or CCF, acts like a shutter to the brain, preventing an onslaught of outside stimuli from entering unchecked into the mind and bombarding the unconscious. Simultaneously though, it impedes concentration, fast absorbing of knowledge and the ability to lock on to a single subject. It also prevents a person from accessing his own inner mind, the door to the soul, a point vividly described by the great kabbalist, Chief Rabbi of Haifa in the early twentieth century, Rabbi Naftoli Herts:
"There is nothing in the physical that cannot be seen in its spiritual form (through the soul’s insight). Man however, while living in this world, will only be able to see the spiritual if he removes his physicality. It is [thus] written, “And He placed to the east of the Garden of Eden the Kerubim and the sharpness of the revolving sword to guard the way to the Tree of Life”(Gen. 3:24).
This refers to two factors that prevent a person from perceiving the spiritual.
1. Man’s physicality, alluded to by the two Kerubim. Like eye-lids covering the eyes, man’s physicality impedes his spiritual understanding.
2. [The ability to fix one’s mind consistently on one thought.] To gain true understanding, a person has to continuously think on the spiritual and not allow any other thoughts to interrupt. Only then can he transcend his physicality. [But] G-d has made man such that his thoughts constantly change from one subject to the next. He finds it very difficult to keep hold of a single thought. The ‘thought’ that interrupts him is like ‘a sword’, cutting and interrupting his flow of thinking. This is the “sharpness of the revolving sword”. Just as there are Kerubim and the sharpness of the sword in the world [in Eden], so there are Kerubim and the sharpness of the sword in man.”
 Sefer HaTseruf 2b. Also Guide for the Perplexed, Introduction (Friedlander, Pg 3).
 Hypnosis is defined as “a state of mind in which the critical faculty of the human is bypassed, and selective thinking established”. Elman, Hypnotherapy, p. 26. (U.S. Gov. Dept. of Educ.).
 See Liqutei MohaRan 1, 24:8.