Psychoanalysis
Ernest Jones contributed the term "rationalization" to psychoanalysis in 1908, defining it as "the inventing of a reason for an attitude or action the motive of which is not recognized"'. Although Jones had not coined the term - the Oxford English Dictionary records the year of its first use as 1846' - he was the first to employ it in the context of psychoanalysis: 'No one will admit that he ever deliberately performed an irrational act, and any act that might appear so is immediately justified by...providing a false explanation that has a plausible ring of rationality'.
The term was taken up almost immediately by Sigmund Freud to account for the explanations offered for neurotic symptoms - 'a process which (borrowing a useful term from Ernest Jones we may describe as "rationalization"' - and was later developed further by his daughter Anna Freud.
However the concept itself (as opposed to the term) can be traced back millennia earlier, to Quintilian and classical rhetoric: 'The "pat excuse" is the color, a frequent technical term among the rhetoricians for any approach that would present an action in the most favourable possible light'. By the eighteenth century, it was almost a commonplace that, were a man to consider his actions, 'he will soon find, that such of them, as strong inclination and custom have prompted him to commit, are generally dressed out and painted with all the false beauties which, a soft and flattering hand can give them'.
What psychoanalysis added was the specific idea of the motives that were glossed or colored being unconscious, a point developed further by Lundhold, "Repression and Rationalization", in 1933, and by Hollitscher, "The Concept of Rationalization" in 1939. By the 1940s Fenichel could distinguish 'various types of rationalization...Emotional attitudes become permissible on condition that they are justified as "reasonable"', but equally 'Defensive attitudes and resistances, which seem irrational because their real purpose is unconscious, frequently are "rationalized" by the ego's foisting other secondary purposes upon them'.
For a near-determinist like Eric Berne, one's 'important decisions are already made...in early childhood': thereafter 'other decisions...are "directed" decisions rationalized on spurious grounds'. Once a decision has been made on unconscious grounds, 'without the individual's being aware of the real forces behind it. he takes upon himself the task of finding justifications for it..."rationalization"'.
Lacan in his concept of meconnaissance came very close to the same idea: 'everything that the ego neglects, scotomizes, misconstrues...everything that it ignores, exhausts, and binds in the significations that it receives from language'.
Some later psychoanalysts might take a more positive view of the process, suggesting that 'Intellectualisation and rationalisation...bridge the gap between immature mechanisms and those of maturity'; but to object relations theory it could be part of a more sinister process whereby the mind 'detaches feelings from their true locus and attaches them to the exact reverse; it falsifies judgement; it splits intellect from feeling and enslaves reason...a process called rationalization'.
Read more about this topic: Rationalization (making Excuses)