In my recent blogs I made a distinction between an action as intended and the side effects of an action, as is done by many philosophers. Often we talk also of the unintended consequences of an action, when we mean its side effects, which is usually distinguished from the intended consequences of this action. That unintended consequences of actions can be seen as side effects does not need to make them less important than the intended main effects. For instance, a side effect of an industry can be that it causes serious damage to the environment and this can be a reason to close down this industry.
Another way of making a distinction between the different effects of an action is talking of actions under different descriptions, an idea introduced by Elisabeth Anscombe. Instead of using the example used by Anscombe, I prefer to take one by Davidson, which I have slightly adapted (Donald Davidson, Essays on actions and events, Oxford: Clarendon Press, 1980; pp. 4-5). Let us say, there is a thief in my house, and the thief knows that, when I come home, I’ll turn the light on and that he will be warned then. Now I come home, I flip the switch, turn on the light, and illuminate the room. Unbeknownst to me I alert also the thief to the fact that I am home. Now we can describe what I did, according to Davidson, in different ways. For example, we can describe what I did by saying that I illuminated the room.
However, we can also say that I alerted the thief, which is a side effect of the action described as illuminating the room.I think that it is right that in many cases we can say that describing an action in different ways is a way of taking account of its side effects and of making clear that an actor is responsible for the side effects in some way. However, not all side effects can be taken account of by redescribing what is done. Take for instance the example in my last blog: a side effect of the First World War was contributing to the development of plastic surgery. Or, in case one finds “First World War” too vague as a description of an action, one can say that the fighting of a soldier in this war contributed to the development of plastic surgery. Can we now say that one description of what the soldier did is fighting and another description is contributing to the development of plastic surgery? I think this is weird. What is then the difference with Davidson’s example? I think it is this. I think that one can defend (which I’ll not do her) that in a certain sense I am responsible for having alerted the thief, but that it is impossible to defend the thesis that the soldier (or “The First World War” whatever that may be) can be held responsible for having contributed to the development of plastic surgery. This contribution is a pure side effect by way of speaking.