Abstract
Causal processes that are technically called deviant or wayward causal chains must be ruled out when analyzing various phenomena, including intentional action, perception, and the operation of causal mechanisms involved in the manifesting of causal powers. Irving Thalberg is incorrect in arguing that this problem does not arise when analyzing intentional action. After criticizing solutions proposed by Christopher Peacocke and David Lewis, I provide a general analysis of non-deviance. In application to intentional action, the account is seen to be preferable to that of Michael H. Robins, and proves to be adequate to rule out what Alfred R. Mele calls cases of tertiary waywardness