**Mutually exclusive** is a phrase that may be confusing. We will examine the meaning of the term *mutually exclusive*, when it first appeared and some examples of its use in sentences.

*Mutually exclusive* describes two events, ideas, goals, etc., that may not both be true or both exist. In a situation in which two things are *mutually exclusive*, one thing precludes the other from occurring or from being true. The phenomenon of *mutual exclusivity* is prominent in logic and probability theory, which state that two propositions that are *mutually exclusive* can not both be true. Some things that are *mutually exclusive* are jointly exhaustive, meaning that either one thing or the other must be true. For example, when a coin is flipped the two possibilities are that the coin will land on heads or tails. One of these possibilities must be true, and the other possibility is therefore not true. In other situations of *mutual exclusivity*, a *mutually exclusive* outcome is not jointly exhaustive. For instance, when throwing a standard die there are six possibilities for an outcome. The chance that the number two and the number six will come up are *mutually exclusive*, only one of these numbers may show at a time. However, If the number two doesn’t come up it is not a given that the number six will come up, as there is a possibility that the number one, three, four, five or six will come up. The term *mutually exclusive* first appeared sometime in the 1870s.

Examples

The two aren’t mutually exclusive, he said, but there seem to be two “camps” in town on the issue, which is what Shipp said separates him from Harvell. (The Bryan-College Station Eagle)

The irony is that experience (i.e. age) and younger generational whims are somewhat mutually exclusive and to the extent that experience doesn’t amount to squat. (The Charleston Post and Courier)