The term equifinality was popularised in the 1950s by the biologist and systems theorist Ludwig von Bertalanffy.

This is where equifinality comes in: different starting points and different causal sequences can lead to the same final state, provided the system can organise itself actively as it evolves.

The idea was taken up by cyberneticists, notably Heinz von Foerster, and by systems thinkers — Gregory Bateson, Paul Watzlawick, Humberto Maturana — who showed that a system’s behaviour depends less on its past than on its present regulation. Causality becomes circular, effects feed back on causes, and the system keeps inventing new routes of self-reorganisation.

In human systems the principle holds everywhere. Two children from very different backgrounds may both become teachers or therapists. Two companies with opposite strategies may reach the same profitability. Two couples with chaotic emotional histories may, in time, build a stable relationship.

That is equifinality: the functional convergence of divergent trajectories.

Equifinality goes beyond strict systems logic to meet a philosophy of complexity. It accords with Gilles Deleuze’s thought, which proposes a non-linear, non-hierarchical vision of becoming. In A Thousand Plateaus he writes that every multiplicity is defined by its lines of flight: there is no single origin and single destination, but an infinity of possible paths weaving a becoming. Equifinality is a way of saying that the real will not be locked into rigid causality.

As for Gilbert Simondon, he explains that individuation — the way an individual comes to be constituted — is not a mechanical derivation from past causes. It is a dynamic process in which several heterogeneous tensions can resolve into a coherent form. Here too, the same level of individuation can emerge from very different gestations.

Equifinality is not a soft relativism. It does not say that everything is equivalent, nor that all trajectories lead to the same point. It says something finer: different itineraries may produce a comparable function, result or effect, without the routes being interchangeable. What varies is not only the form, but the meaning, the emotional charge, the memory of the journey.

In therapeutic or educational work this implies attention to the diversity of paths. There is no single right way forward, nor a single road to resilience, success or inner peace. The practitioner must be able to recognise and support heterogeneous processes that each, in their own way, tend towards a constructive reorganisation.