Small Impacts and Imperceptible Effects: Causing Harm with Others

In an increasingly crowded and interactive world, there are more and more ways to harm people in an indirect way. These “new harms” (Lichtenberg, 2010, 558) are typically caused by many hands (Thompson, 1980). Many people use too many plastic bags, drive their cars too much, eat too much meat or bluefin tuna, drink bottled water, et cetera. Each individual act has a negligible effect, and may, as a singular act, not be harmful—but the same act performed by millions is. This gap between the (almost or perhaps entirely) harmless singular act and the harmful performance of the same act by many spells trouble for the moral evaluation of these acts and for assigning responsibility. In a recent article, Shelly Kagan (2011) tries to dissolve some of these difficulties. In essence, Kagan claims that many small contributions must always encounter a threshold such that a relevant harm is triggered. If that is so, Kagan argues, any single action contributes to expected harm because there is a non-zero probability that it crosses the relevant threshold. Julia Nefsky (2011) pokes holes in Kagan’s argument, showing that Kagan proceeds too quickly in dismissing the challenge of sorites-like situations where each additional action does not add additional perceived harm. This exchange shows that the issue of imperceptible effects and harms is still not