The mind is basically a system of communication and control between the thetan , the spiritual being that is the person himself, and his environment. It is composed of mental image pictures that are recordings of past experiences.
The individual uses his mind to raise and solve problems related to survival and to direct his efforts according to these solutions.
The analytical mind is the rational one, the conscious mind that thinks, observes data, remembers them and solves problems.
The reactive mind is the portion of the mind of a person who works on a totally stimulus-response basis. It is not under voluntary control, and exerts its strength and power of command over consciousness, purposes, thoughts, body and actions.