Is close enough good enough?

Should we allow grave harm to befall one individual so as to prevent minor harms befalling sufficiently many other individuals? This is a question of aggregation. Can many small harms 'add up', so that, collectively, they morally outweigh a greater harm? The 'Close Enough View' supports a moderate position: aggregation is permissible when, and only when, the conflicting harms are sufficiently similar, or 'close enough', to each other. This paper surveys a range of formally precise interpretations of this view, and reveals some of the problems they face. It also proposes a novel interpretation which avoids these problems.