Power can take many forms, such as wealth, armaments, civil authority, and influence over opinion. Power is the fundamental concept in social science, just as energy is the fundamental concept in physics. There are different types of power, including priestly power derived from religion, kingly power connected to divine origins, naked power involving no subject acquiescence, revolutionary power depending on revolution, and economic power which is derivative and depends on law. Power is defined as the ability to produce intended effects and instruct others to act in a desired way.