In Mt. Healthy City School District Board of Education v. Doyle, the Supreme Court established a rule of causation to distinguish between a result caused by a constitutional violation and one not so caused by establishing "the proper test ... which likewise protects against invasion of constitutional rights without commanding undesirable consequences not necessary to the assurance of those rights." Reconciling such inconsistencies is similar to the type of situation that has confounded physicists trying to achieve a unified field theory-a theory capable of describing nature's forces within a single, all-encompassing, coherent framework. Physicists since Einstein have sought such a "unified field theory" or a "theory of everything" to fashion the ultimate theory of the universe and to answer questions as to causation and how the universe arose (and to explain the universe from the "big bang" to the end, or the "cosmic implosion"). However, they encountered a major causation problem:
The problem is this: There are two foundational pillars upon which modern physics rests. One is Albert Einstein's general relativity, which provides a theoretical framework for understanding the universe on the largest of scales: stars, galaxies, clusters of galaxies, and beyond to the immense expanse of the universe itself. The other is quantum mechanics, which provides a theoretical framework for understanding the universe on the smallest of scales: molecules, atoms, and all the way down to subatomic particles like electrons and quarks. Through years of research, physicists have experimentally confirmed to almost unimaginable accuracy virtually all predictions made by each of these theories. But these same theoretical tools inexorably lead to another disturbing conclusion: As they are currently formulated, general relativity and quantum mechanics cannot both be right. The two theories underlying the tremendous progress of physics during the last hundred years-progress that has explained the expansion of the heavens and the fundamental structure of matter- are mutually incompatible.
On a less universal scale, courts have struggled with causation issues that can answer the following questions: (1) whether rights have been violated and, (2) if so, whether the violations are the cause of decisions or should be used to negate, or end, decisions. Just as physicists must try to reconcile inconsistent theories, courts must determine whether various laws have been violated and must preclude various decisions when mixed motives are present--one legitimate and one unlawfully discriminatory-and when both may have caused an unfavorable employment action. This has been a major problem in connection with labor and employment matters, and the resolution of the mixed-motive problem came from the framework established in Mt. Healthy.
Fleming, Joseph Z.
"Mt. Healthy, Causation and Affirmative Defenses,"
Mercer Law Review: Vol. 51
, Article 6.
Available at: https://digitalcommons.law.mercer.edu/jour_mlr/vol51/iss2/6