Nathaniel Branden (1930-2014) was a Canadian-American psychotherapist and writer renowned for his pioneering work in the psychology of self-esteem. He authored nearly 20 influential books, including the seminal "The Psychology of Self-Esteem" and "The Six Pillars of Self-Esteem." Branden's career spanned over seven decades, during which he contributed significantly to the evolution of self-esteem as a psychological concept. He founded The Branden Institute for Self-Esteem in Los Angeles, where he worked as a therapist and corporate consultant. Branden's early career was marked by his association with philosopher Ayn Rand, helping to develop and promote her philosophy of Objectivism. After their acrimonious split in 1968, he focused on developing his own psychological theories and therapeutic approaches. Branden's work emphasized the importance of self-responsibility, self-assertiveness, and personal integrity in achieving a fulfilling life. He was known for his clear teaching style and ability to translate complex psychological concepts into practical, actionable advice. Branden passed away in Los Angeles, leaving behind a legacy that continues to influence the fields of psychology and personal development.