What characteristic differentiates self-perpetuating systems from others?

Self-perpetuating systems are defined by their ability to sustain themselves over time without the need for external input. This characteristic implies that once established, these systems have internal mechanisms that allow them to maintain their processes and functions independently.

For instance, in the context of policing, such systems might refer to organizational structures or practices that continue to operate and evolve based on their internal dynamics and resources, rather than relying heavily on external motivators or interventions.

Other options do not capture the essence of self-perpetuation. For example, reliance on external stimuli would typically characterize systems that need outside forces to continue functioning, while being purely mechanical does not encompass the complexity often found in self-sustaining frameworks. Continuous feedback, while important in many systems, especially in adaptive scenarios, does not fully define self-perpetuation, as it may imply a dependency on inputs from outside rather than self-sustainability. Thus, sustaining themselves over time is the defining feature of self-perpetuating systems.