A whole person is contained in a flake of dead skin peeling off after too much sun exposure. The smallest cell contains the whole organism, and it all begins with the smallest possible unit, growing and multiplying, then dwindling and dying.
Similarly, an idea contains a whole world of possibilities, crossroads, contingencies but also a measure of necessity, the result of a host of other contingencies, organising themselves and clustering together for cooperation or competition. Ideas emerge when the soil is ripe, but the soil is not enough to explain why one idea takes off while another dies out. All ideas are time- and location-specific, and while a number of causes may account for their success, an emergent idea ultimately defies explanation. We may try to explain why Christianity or Marxism became popular ideas in history, every explanation will be provisional, subject to improvement and review.
Everything begins with a droplet, a cell, a word, a gesture. It’s up to us to see the tear inside the tear, the tidal wave within the globule, the earthquake stirring within the roar.