Sigmund Freud was an Austrian neurologist and the founder of psychoanalysis.
Albert Ellis was an American psychologist and creator of Rational Emotive Behavior Therapy, a precursor to Cognitive Behavioral Therapy.
Aaron Beck was an American psychiatrist and psychotherapist, widely regarded as the father of cognitive therapy and a pioneer in the treatment of depression.
Virginia Satir was a pioneering American therapist and educator, renowned for her innovative work in the field of family therapy.
Viktor Frankl was an Austrian neurologist, psychiatrist, and Holocaust survivor who developed logotherapy, a psychotherapeutic method focused on finding meaning in life.