The Concept of Anxiety
All of Kierkegaard's books have either a preface, dedication, or prayer at the beginning. This book includes a lengthy introduction. "The Concept of Anxiety" was published on exactly the same date as "Prefaces", June 17, 1844. Both books deal with Hegel’s idea of mediation. Mediation is a common thread throughout Kierkegaard’s works. His work up to this point was to show that faith was being mediated by knowledge. Here he takes up the questions of sin and guilt.
George Humphrey (psychologist)
In 1951, he wrote "Thinking: An Introduction to Its Experimental Psychology", which had considerable success as it provided a written description of all research done on mental problem solving in humans conducted by Otto Selz, the Würzburg School, and other Gestalt psychologists. Their findings largely supported Humphrey's assertion—discussed in his book "Directed Thinking" (1948)—that a sequence of thoughts is governed by motivation.