It is common for arguments to conclude that one thing causes another. But the relation between cause and effect is a complex one. It is easy to make a mistake. In general, we say that a cause C is the cause of an effect E if and only if: (1) Generally, if C occurs, then E will occur, and (2) Generally, if C does not occur, then E will not occur either. We say “generally” because there are always exceptions. For example, we say that striking the match causes the match to light, because: (i) Generally, when the match is struck, it lights (except when the match is dunked in water), and, (ii) generally, when the match is not struck, it does not light (except when it is lit with a blowtorch). Many writers also require that a causal statement be supported with a natural law. For example, the statement that “striking the match causes it to light” is supported by the principle that “friction produces heat, and heat produces fire”.
- Complex Cause
A single cause is identified when the effect is actually caused by a number of interacting objects or events.
One thing is held to cause another, and it does, but it is insignificant compared to other causes of the effect.
- Joint Effect
One thing is held to cause another when in fact both are the effect of a single underlying cause.
- Post Hoc
Because one follows another, it is held to be caused by the other.
- Wrong Direction
The relation between cause and effect is reversed.