I'm looking for either a word or a phrase meaning "from many to one" or "from complexity to singularity".
An attempt or tendency to explain a complex set of facts, entities, phenomena, or structures by another, simpler set: "Science requires some degree of reductionism, some picking apart and focusing on one or two variables at a time" (Natalie Angier).
Ockham's razor n. A rule in science and philosophy stating that entities should not be multiplied needlessly. This rule is interpreted to mean that the simplest of two or more competing theories is preferable and that an explanation for unknown phenomena should first be attempted in terms of what is already known. Also called law of parsimony.
(Philosophy) a maxim, attributed to William of Ockham, stating that in explaining something assumptions must not be needlessly multiplied. Also called: the principle of economy
Let's get down to the nub of this.
SYNONYMS quintessence, soul, spirit, ethos, nature, life, lifeblood, core, heart, centre, crux, nub, nucleus, kernel, marrow, meat, pith, gist, substance, principle, central part, fundamental quality, basic quality, essential part, intrinsic nature, sum and substance, reality, actuality
to combine or unite to form one organization or structure