 Similar microfoundational accounts must be given in support of the idea of "causes in history". Once established, it is reasonably straightforward to see how a social structure such as a property system or an ideology "causes" a historical outcome: by constraining the choices of actors and contributing to their motivations and values in the choices they make, a structure or an ideology influences historically important events like social movements, market crashes, or outbreaks of ethnic violence. Structures influence individual actors, and individual actors collectively constitute structures. This approach gives a basis for judging that such-and-so circumstance “caused” a given historical change; but it also provides an understanding of the way in which this kind of historical cause is embodied and conveyed—through the actions and thoughts of individuals in response to given natural and social circumstances.