|Wrong direction is a logical fallacy of causation where the actual cause and effect are reversed. The cause is said to be the effect and vice versa.
Wikipedia’s discussion of this fallacy is confusing insofar as, after giving a definition similar to the one above, they then go on to introduce examples where cause and effect are unclear, rather than factually known. But cases where the cause is unclear are already described by cum hoc ergo propter hoc (which was the subject of episode 24) or post hoc ergo propter hoc (episode 47). Therefore in this discussion I shall adhere strictly to the definition above; that is, the cases where cause and effect are factually known but fallaciously reversed.
The reasoning was that the people got sick because the lice left. The real reason however is that lice are extremely sensitive to body temperature. A small increase of body temperature, such as in a fever, will make the lice look for another host. The medical thermometer had not yet been invented, so this increase in temperature was rarely noticed. Noticeable symptoms came later, giving the impression that the lice left before the person got sick.
This is a wrong direction fallacy because the preponderance of evidence is that most apparent terrorism is covertly carried out by, or instigated by, security agencies. So the actual causal relationship is that it is the power of the security agencies that ultimately causes terrorism.
This is a wrong direction fallacy because the harmful social effects of narcotic drugs are mostly caused by their illegality. In the typical case, a narcotic drug had less problems associated with it before it was made illegal as compared to after it was made illegal.