The runaway train

Canadian Broadcasting Corporation

PIRIE, MADSEN (2006)(2015) How To Win Every Argument, Bloomsbury, London.

The runaway train

The runaway train fallacy occurs when an argument used to support an action, would also further support an action. The argument needs to stop at a particular point...(180).

The author's example:

Lowering the highway speed limit from 70 mph to 60 mph might save lives. (180).

Lowering the highway speed limit from 70 mph to 50 mph might save even more lives. (181).

Lowering the highway speed limit from 70 mph to 40 mph might save even more lives. (181).

The speed limit at 0 mph would save the most lives. (181).

This type of fallacy, according to Pirie, occurs when someone advances a general argument for something the arguer regards as a special case. (182). Should the argument only be limited to a special case or should it have more general ramifications? (182).

To counter this fallacy, with the example provided, premises and conclusions which support higher speed limits should also be considered. Lower speed limits may save more lives, but the effects on transportation, the economy, etcertera, need to be considered.

Further:

There are drivers that drive at higher speeds in a careless fashion.

There are drivers that drive at lower speeds that continually hit the brakes. This could lead to accidents and even multi-car accidents.

Both these groups are potentially, dangerous drivers.