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.
The Concept of Mind
The Concept of Mind is a 1949 book by philosopher Gilbert Ryle, in which the author argues that "mind" is "a philosophical illusion hailing chiefly from René Descartes and sustained by logical errors and 'category mistakes' which have become habitual." The work has been cited as having "put the final nail in the coffin of Cartesian dualism" and has been seen as a founding document in the philosophy of mind, which received professional recognition as a distinct and important branch of philosophy only after 1950.