Niyati

The claim

Niyati is not merely the view that events have causes. It is the stronger claim that the entire sequence of a being's births, experiences and eventual release is settled, and that nothing done within that sequence changes it. Purity and defilement occur without cause; there is no power in the will, no efficacy in action, no room for merit.

The image reported for it is a ball of thread thrown so that it unrolls to its length and stops. The number of births is fixed, and liberation comes when they are exhausted.

Against karma

This put the Ajivikas directly against the Buddhists and Jains, both of whom made action and its consequences central. If niyati holds, the whole apparatus of karma, moral responsibility and the graded path is empty, and the discipline both traditions demanded is pointless.

Both attacked it accordingly and at length, and it is in their attacks that the doctrine survives.

The puzzle

Ajivika practice was severely ascetic, which is difficult to reconcile with a doctrine that makes effort useless. Proposed resolutions include that the austerities were themselves fated and performed without expectation, that they marked membership rather than pursued a goal, or that the reported doctrine is a hostile simplification of something more qualified.

There is no way to test these, since the order's own texts are lost. The tension is worth noting rather than resolving, because it is a good indication of how partial the surviving record of the heterodox schools is.