The thesis advances a novel internal causal pluralism, based on interventionist causal models. I argue that a deeper understanding of causal reasoning can be achieved by distinguishing a plurality of causal concepts within the interventionist framework. Particular focus is laid on the term actual causation, which has been used to describe three features of causal reasoning. First, it describes token causes (as opposed to type causes), second it concerns causes that in fact bring about an effects (as opposed to merely potential causes) and, third, it describes causes that are taken to be particularly salient (as opposed to mere background conditions). The disambiguation provides the basis for a new taxonomy of causal claims that I develop in the first chapters of the thesis. The taxonomy sheds new light on causal reasoning in three specific contexts that are examined in detail in the subsequent chapters. First, I discuss causal reasoning in the context of scientific discovery on the example of the discovery of the Cosmic Microwave Background. Second, the role of norms in disagreement over causes is examined. Third, I provide an analysis of the role that causal reasoning plays in intervention and responsibility.