Etiology is the study of a cause, or causation, while teleology is the study of the purpose of a phenomenon.

When we focus too much on etiology we become deterministic: this was caused by that. We are detectives uncovering the cause-effect relationship and we allow ourselves to be determined by the past.

When we focus on teleology we look for “the role” achieved by a phenomenon/behavior to uncover its “goal.” Not what caused it, but what is its purpose. As in, “Why do you insist on letting your past control your present?” 

The answer is often because it serves me well to blame the past rather than undertake the hard work of changing in the present. 

“People are not driven by past causes, but move toward goals that they themselves set.”

The Courage to be Disliked