It is a necessary characteristic of scientific experiments. It is a relationship of events that substantiates the belief that natural phenomena do not occur randomly. It enables predictions to be made. The advent of chaos theory has caused some rethinking of this principle. The acceleration of a cart depends on the unbalanced force acting upon the cart.
Every event has a cause.
It does not happen by itself. Patterns can be identified in nature. From those patterns inferences can be made. An understanding of the finite nature of the world's resources, and an understanding of the necessity to treat those resources with prudence and economy, are underlying principles of conservation. In physics, the term 'conservation' also has a unique meaning, as in the conservation of energy.