Hypnosis is a completely natural state of mind. You enter this state many times a day without consciously realising that you are in a light trance state. When you are driving and you accidentally miss your intended turn, when you are watching a movie or daydreaming and everything else falls away to the point that you are not aware of anything else, even if only for a moment. These are examples of very light trance states, a self-induced hypnotic state. When you are watching T.V. you are under hypnosis.
When you are in this state of mind, the critical factor of the mind is relaxed. For example, when you watch a movie, you are completely aware that you are in an auditorium, surrounded by other people, watching a flat screen with a projected image and recorded sound, yet you suspend your disbelief and consciously enter into a state of consciousness where you may feel genuine emotions, forget that you are surrounded by other individuals, or perhaps you don’t even notice the theater any longer. Your logical mind or critical factor is still there, but imagination and emotion from the subconscious mind emerges and overrides it.
The relaxed critical factor facilitates communication between the conscious and the subconscious mind. Hypnosis works in the same way, offering the client an opportunity to relax their critical factor, their conscious thought process, and access their feelings, physical body and internal processes at a much deeper level.