To “affirm” is “to make firm, to confirm or ratify.” It is also “to assert positively, to say with confidence, to aver.” (I wonder whether this second meaning slid sideways into the lexicon in inverse of the manner that ghastly “compersion” entered, that is, a meaning forced against the term.) This second definition seems to be wherefrom the popular terminology derives. In logic, one engages in rigorous practice and process to affirm things to be true; in psychological pseudoscientific interventionist auto-bolstering, one abandons the notion of rigorous inquiry entirely, and instead affirms oneself.
I am advised that an “affirmation” is a positive statement that aims to reinforce an individual’s self-regard and thereby, integrity. It appears this is supposed to work through the reinforcement of both repetition, and through reassuring oneself that the statement (and not, say, reality around oneself, or the feared unknown that has not yet come to pass) is the truth of the matter, which reassurance calms the panic that derives from such dubiously horrifying dangers as “loss of self regard” or “loss of social status.”
More practically: “affirm” comes from the Latin ad, “to,” combined with firmare, to “strengthen, make firm,” which itself comes from firmus, “strong.” Affirmations make one strong. Unlike prayer (from Latin precari, “to ask, beg, pray”), rather than ask the affirmation aims to wield words to make something be true. One’s helped when one helps oneself, and in this sense, an affirmation is a form of spiritual jumper cable.
As hopelessly corny and ridiculous as affirmations (and their dubious cousin, “positive self talk”) may seem, they have real practical application. When one abides in a state of chronic auto-casigation and condemnation for the fault about to be committed, one in fact is making a prediction, which— not only being presumptuous— also forces the hand of fate, to make one’s dour tidings into lived reality; and once misstep is made, one is flung back onto a bed of one’s own vitriol to rot.
One must make affirmations for oneself, bespoke for each situation. To consult a manual seems like a kind of cheating on par with an act that would invite possession. Why would anyone want to invite a stranger’s words to take up residence in the mind to govern one’s self-conception? One must discern which statements are most deeply needed by the earthly part of oneself, and gently repeat and reinforce them, and thereby guide oneself through into a future that is always uncertain.