Noun
external cause (plural external causes)
(medicine) A cause for an effect in a system that is not a constituent of that system, especially causes of personal health problems or death, such as poison, weapon wounds, or accident.
The whole contains nothing which is not or its advantage; and all natures indeed have this common principle, but the nature of the universe has this principle besides, that it cannot be compelled even by any external cause to generate anything harmful to itself. Marcus Aurelius
God, our genes, our environment, or some stupid programmer keying in code at an ancient terminal - there's no way free will can ever exist if we as individuals are the result of some external cause. Orson Scott Card
Sensation is not the conduction of a quality or state of external bodies to consciousness, but the conduction of a quality or state of our nerves to consciousness, excited by an external cause. Johannes Peter Muller