lies beyond the remit of this essay. Suffice to say that the most enduring and fundamental
of Freud’s discoveries is that of the unconscious – “there is this secret, hidden, dissociated personality, and...this personality has a tremendous effect on everything we do, and everything we think” (Fromm, 1955). Everything we think and do has an identifiable cause, and nothing is accidental as Freud reminds us in both The Psychopathology of Everyday Life (1901) and The Interpretation of Dreams (1900).
One of the key tenets of psychoanalysis, which provides the underlying rationale for free association, is the principle of psychic determinism, defined by Angel (1959) as “the application of the causality principle to psychic occurrences”. Nothing happens by chance or in an accidental, arbitrary way. Each psychological event is determined by events which preceded it, and occurrences in our psychological lives that appear to be random only appear so (Brenner, 1999). Thus, there is nothing accidental about a casual remark or slip of the tongue (also known as a paraprax or Freudian slip), which is thought to reveal an unconscious belief, thought, or emotion.
The concept of psychic determinism also helps to explain other psychological processes such as unconscious marital fit, which postulates that there is a corresponding personality fit between partners in a relationship that is both unconscious and fulfils certain needs (cf. also the concept of interpersonal chemistry which is central to Goethe's novel Die Wahlverwandtschaften, known in English as Elective Affinities).
