Page "EPR paradox" Paragraph 33

The principle of locality states that physical processes occurring at one place should have no immediate effect on the elements of reality at another location.

At first sight, this appears to be a reasonable assumption to make, as it seems to be a consequence of special relativity, which states that information can never be transmitted faster than the speed of light without violating causality.

It is generally believed that any theory which violates causality would also be internally inconsistent, and thus deeply unsatisfactory.