Plato gives the three sisters their most elaborate setting, and it is one in which Clotho is not a weaver at a loom but an operator of the cosmos. In the myth of Er at the close of the Republic the three sit on thrones at equal intervals around a great spindle turning in the lap of Necessity. Lachesis sings of what was, Clotho of what is, and Atropos of what will be. Clotho lays her right hand on the outer circumference of the whorl and helps it turn, Atropos touches the inner circles with her left, and Lachesis takes hold of both in turn.
The division of labour is exact and it is not the one the older poets used. Clotho has the present, and the present is the whole outer sphere, the fixed stars, the movement that carries everything else with it. She confirms what has been chosen rather than choosing it: in the myth a soul picks its own next life before Lachesis, and it is then brought to Clotho, who ratifies the choice under her hand, and only afterwards to Atropos, who makes the spun thread unalterable. Plato has kept the three names and the sequence and quietly moved the responsibility onto the person whose life it is.
Cult treated her more simply. Greek practice approached the Moirai at the thresholds of a life rather than through large public festivals, and the offerings recorded for them are the modest ones appropriate to a household observance rather than a civic one. The philosophical picture and the domestic one sat side by side without either replacing the other.