2. Fallacies of the argument from cause to effect.
Fallacies of the argument from cause to effect may be exposed by showing
1. That the observed cause is insufficient to produce the alleged effect.
2. That past experience shows that the alleged effect does not always follow the observed cause.
3. That an independent force has intervened to prevent the observed cause from operating.
4. That the conclusion established by the argument is overthrown by positive evidence.
It must be kept in mind that the argument from cause to effect is subject to errors similar to those discussed in connection with fallacies of the argument from effect to cause. In his desire to predict the course of future events man is led to ignore the complex nature of human affairs. A certain individual believes that if he puts all his money into a business and then gives all his attention to its management that that is a sufficient cause for success. Nevertheless, so much depends upon the nature of the man and of the business that it is extremely difficult to foretell the effect. The principle underlying this situation is common to practically every argument from cause to effect. Unless the fallacy is obvious it requires a broad and penetrating intellect to fathom it.
3. Fallacies of the argument from effect to effect.
The fallacies of the argument from effect to effect are discovered by resolving it into the argument from effect to cause and from cause to effect, of which it is composed, and examining the validity of each of these processes.