Comparative process tracing would be futile if it required comparing all stages of the process between model and target species or population.

Comparative process tracing would be futile if, in order to know that C causes E in the target species or population, we would have to compare all the stages of the process between model and target. This is because in order to do so, we would have to know all stages of the process through which C causes E, but if we did, we would already know that C causes E. This brings us back to the extrapolator’s circle. Steel now argues that comparative process tracing avoids the extrapolator’s circle by de