False Dichotomy

In any debate, including employment litigation, the parties must state their premises. When put to the task, there is not limit to the mistakes -- both deliberate and inadvertent -- which can skew an argument. As such, litigators must be on the lookout for logical fallacies in both opponent's and their own writing and oration. As a primer, I will work on one such fallacy each week.

When stating the premises, the arguer might say something like "If its not A, it must be B." Unless both A and B have been established as the only alternatives, then this statement is false. That is called a false dichotomy or false dilemma. Stated succinctly:

Arbitrarily limiting a range of possibilities to only two is a false dichotomy.

Similarly, Arbitrarily limiting a range of possibilities to a subset of the whole is a false dilemma. See another definition here.

For instance, if an employee's performance become suddenly erratic, and workplace issues are eliminated, presuming the employee has a drinking problem presents a false dichotomy: either the employee had a workplace problem or a drinking problem. On the other hand, when an employee attributes "stress" to his job without proper medical examination: the employee is assuming that work must be he cause, since his home life is good.

The results of an argument from false premises is also false, so be on the lookout for this sort of thinking!