That an action of ours would harm or impose a burden on someone is a reason for us not to do it. What if it would harm many people? Do we then have many reasons, and do these ‘add up’? It is hard to find an answer that is acceptable in all cases. Unrestricted aggregation would permit us to inflict a severe harm on one person in order to prevent only comparatively trivial harms to a great number of people. On the other hand, a complete ban on aggregation would mean that preventing a greater harm must always take priority over preventing any number of lesser harms even when the difference is only very slight. Many would be reluctant to accept either of these consequences. A moderate view, which allows aggregation sometimes but not always, seems therefore desirable. This paper considers a view of this kind, sometimes called the ‘Close Enough View’. The idea is that aggregation is appropriate only when the harms involved are ‘close enough’, when they differ ‘in degree’ but not ‘in kind’. I will suggest two approaches to developing this view and consider some problems that they face.