Psychology is the science that studies the attributes and characteristics which certain living organisms possess by virture of being conscious. (page 3-4, pbk)
Living organisms differ in their consciousness by their range of awareness. Man's high degree of awareness is the highest known to man. Man's high range is made possible by man's conceptual capacity. Man's conceptual capacity is run volitionally by his reasoning capacity. Because of the foregoing (and other Objectivist and Biocentric arguments) we define human psychology as the science that studies the attributes and characteristics which man possesses by virutue of his distinctive form of consciousness which IN MAN'S CASE is his rational-volitional conceptual faculty on top of his automatic perceptual faculty.
Man's distinctive nature is his ability to form concepts: the conceptual level of dealing with reality is man's way.
Theory is speculating about what should be true based on what is true.
Therefore, theoretical psychology is speculating about what should be true of human beings based on what is true about their psychology and using these speculations to postulate what human beings should do to solve their psychological problems and actualize their human potential.
For example, guilt subdues self-assertiveness is a truth, a principle about what is true of human beings. Consequently, we can speculate that if we are un-assertive to a degree we deem excessive and we desire to change it we should look at our guilty feelings. That is we should explore and trace those feelings to their source so as to challenge and correct the errors at their roots.*
There are at least two "givens" in the foregoing:
The first is a choice, the second is not.
The first is a value-choice for you --it is possible for you to choose "humility" over self-assertion.
The second, to repeat, is not a choice in the sense you can change "it" --the reality of it-- by an act of will. "It" is a metaphysical fact and as such it is outside the will.
The second one entails, rather, a choice in the sense that you choose whether or not to notice what it is you are doing when --say for example, after discovering in therapy or in Life or in both, quite a few of your own irrational "shoulds"-- you "hear" yourself (and/or a significant other and/or your Therapist) think and/or say:*
"...you should not have any shoulds"
If after this you don't change therapists it is your choice.
Choice, that is volition, entails both the choice to think and the choice to be aware.