Nathaniel Branden (born Nathan Blumenthal; April 9, 1930 – December 3, 2014) was a Canadian–American psychotherapist and writer known for his work in the psychology of self-esteem.

After getting failing grades as a result, he convinced his mother to send him to a special accelerated high school for adults, and subsequently did well in that environment.

[12] Branden's work at NBI included translating the principles expressed by Rand in her fiction and non-fiction writing into a systematized construct that became known as Objectivism.

[13] In 1968, Rand publicly broke with Branden and published an article denouncing him and accusing him of a variety of offenses, such as philosophic irrationality and unresolved psychological problems.

[15] (Branden later explained in his memoir that he and Rand had in fact been romantically intimate for a period of time in the late 1950s; see personal life.)

Though he remained supportive of the broad essentials of Rand's philosophy, he eventually offered criticisms of aspects of her work, naming as problems a tendency to encourage emotional repression and moralizing, a failure to understand psychology beyond its cognitive aspects, and a failure to appreciate adequately the importance of kindness in human relationships.

[16] He also apologized in an interview to "every student of Objectivism" for "perpetuating the Ayn Rand mystique" and for "contributing to that dreadful atmosphere of intellectual repressiveness that pervades the Objectivist movement.

"[17] Branden argued that self-esteem is a human psychological need and that to the extent this need remains unmet, pathology (defensiveness, anxiety, depression, difficulty in relationships, etc.)

In a piece from 1973, he characterized his mode of therapy as consisting of four aspects: education, emotional unblocking, stimulation of insight, and encouragement of behavior change.

[26] In the context of these troubles, and Rand's reported frustrations in her own marriage, Branden and Rand—who had a passionate philosophic bond—developed amorous feelings for each other and began a love affair in 1954.

[26] Branden reported that in this period Rand began seeking a resumption of their affair; his own marriage, meanwhile, was deteriorating, although he and Barbara were becoming closer as friends.