B.F. Skinner wrote many books and hundreds of articles about behavior theory, reinforcement, and Learning Theory. He was against studing the unconsious mind, and believed the only thing worth studing was outward behaviors. Today, he is now known as one of the most published psychologists. http://allpsych.com/biographies/skinner.html
Carl Rogers was a Humanistic Psychologists who believed that there was good in every person. He is famous for his approach to treating clients. In his published works he taught that it was best to have an “non-judgmental attitude” when treating patients. He held that the client had the answers to their problems and it was the job of the therapists to guide them to the answer. http://allpsych.com/biographies/rogers.html
John Watson is known as the be the father of behaviorism. He was opposed to studying the unconcious mind and believed that only outward behavior can be studied. This strong opposition almost split psychology into two different schools of thoughts. http://allpsych.com/biographies/watson.html
Freud published a book in 1900 called, The Interpretation of Dreams. This book fueled interest in the unconsious mind. He continued to develope many theories that still hold true today. http://allpsych.com/biographies/freud.html
William James is known as the father of American psychology. He formulated a theory in the 1890s called functionalism. This theory paralleled Darwin’s evolution theory and said that man’s mind evolved over time as the need for it grew. James also published several books in the late 1800s and early 1900s on psychology. http://intropsych.com/ch01_psychology_and_science/james_and_functionalism.html