The concept of defense mechanisms has problems and deficiencies, the most serious its neglect of unwitting, but conscious mental activity in the defense process. Clinical observation shows that individuals, not conscious of their purpose, reflexively think and act in ways that forestall or dispel anxiety. Contrary to Anna Freud's claim, the process of defense is in some measure observable. Self-deception by subjects of coercion can be seen also as a defense against external threat similar to that of internal threat.