ab initio

aluksi puhekieltä From the time when a legal document comes into force. (defdate)(R:SOED5)
puhekieltä Calculated from first principles, i.e. from basic laws without any further additional assumptions.
1983, Monty Python, w:Monty Pythons The Meaning of Life|The meaning of life, at about 1h 15:

(..) this soul does not exist ab initio, as orthodox Christianity teaches; it has to be brought into existence by a process of guided self-observation. However, this is rarely achieved, owing to man's unique ability to be distracted from spiritual matters by everyday trivia.