This chapter clarifies the notion of an intervention and compares my version of this notion to the characterizations provided by other writers such as Glymour and Pearl. Very roughly, an intervention on a variable X with respect to a second variable Y is a special sort of causal process that changes the value of X in such a way that any change in the value of Y can occur only as a result of the change in Y. The chapter also discusses the relata of the causal relationship, causal realism, agency theories of causation, and the relationship between my account of causation and that of David Lewis.
Keywords: intervention,, causal relata,, causal realism,, agency theories of causation,