We must find alternatives to the automobile

Note that in writing PI, we added the quantifier 'all'; this makes for a somewhat awkward sentence, but such awkwardness is a price we sometimes have to pay for the sake of explicitness. Now assume you really do believe PI. This argument is deductively valid. However, you must admit that it has a weak point. For P2, as written, is clearly untrue. Some automobiles, for example, are electric, and run on batteries. Since they do not burn petrol (or any other petroleum product), they do not emit carbon monoxide (indeed they do not pollute the air at all). So even if PI is true, you have failed to give a sound argument.

Now you could make the argument inductively sound by changing the word 'All' in P2 to 'Most'. But you could do better, for the following two reasons:

First, it could become false that most automobiles emit carbon monoxide, without any reduction at all in the number of petrol-driven cars, in which case the pollution (and other problems) caused by the burning of petrol might not have been curtailed at all. For it would be possible for a large number of electric cars or other alternatives to be produced over a few years without any reduction in the number of petrol-driven cars. In that case, P2 would be false but you would still want to argue against petrol-driven cars, since they would still be emitting the same amount of pollution.

Second, changing 'All' to 'Most', although it renders the argument sound, does not clarify the issue as much as another alternative.

This other alternative is to change the scope of the generalisation expressed by P2 - in particular, to reduce its scope. Instead of 'All automobiles emit carbon monoxide', we can more accurately write 'All petrol-driven automobiles emit carbon monoxide', rewriting the argument thus:

0 0

Post a comment