Abstract
I argue that, according to ordinary morality, there is moral inertia, that is, moral pressure to fail to intervene in certain circumstances. Moral inertia is manifested in scenarios with a particular causal structure: deflection scenarios, where a threatening or benefiting process is diverted from a group of people to another. I explain why the deflection structure is essential for moral inertia to be manifested. I argue that there are two different manifestations of moral inertia: strict prohibitions on interventions, and constraints on interventions. Finally, I discuss the connection between moral inertia and the distinction between killing and letting die (or doing and allowing harm).