Three millennia ago, the Egyptians began the practice of treating disease by the letting of blood.  Bloodletting became an accepted practice worldwide.  King Charles II and George Washington both endured bloodlettings.  In the 1800s, Dr. Hughes Bennett sparked controversy at the Edinburgh School of Medicine when he published a paper concluding that patient survival rates were not improved by draining blood. 

Why did bloodletting persist as standard practice for at least 3,000 years?   Clearly, the therapy had the weight of history and consensus behind it.  As one physician remarked at the time of the Edinburgh controversy:

"The thinking man", remarked one physician, "finds it hard to believe that the fathers of British medicine were always in error, and that they were bad observers and mistaken practitioners."

William Stokes, "The address in medicine'",  Br. Med J., 1865, ii: 133-142, p. 135 (quoted in J. H. Warner, Therapeutic Explanation and the Edinburgh Bloodletting Controversy: Two Perspectives on the Medical Meaning of Science in the Mid-nineteenth Century, Medical History 245 (1980)).

Last week, Governor Newsom signed AB 2098 (Low) into law.  This new law subjects physicians and surgeons to professional discipline if they "disseminate misinformation or disinformation related to COVID-19, including false or misleading information regarding the nature and risks of the virus, its prevention and treatment; and the development, safety, and effectiveness of COVID-19 vaccines".  The law defines "misinformation" as "false information that is contradicted by contemporary scientific consensus contrary to the standard of care" and "disseminate" as the "conveyance of information from the licensee to a patient under the licensee’s care in the form of treatment or advice".  

Had a similar law been in effect in nineteenth century Edinburgh with respect to bloodletting, Dr. Bennett would have been subject to professional discipline for advising patients not to undergo bloodletting.   In the words of the legislature, the good doctor would have been among "most dangerous propagators of inaccurate information".  The effect of the law would have been to ossify medical treatment to the detriment of patient health and welfare.  

AB 2098 is also oddly specific in targeting "misinformation" only with respect to COVID-19.  Under the well accepted principle of statutory interpretation, expressio unius est exclusio alterius, physicians and surgeons seemingly are not subject to discipline for disseminating disinformation about countless other human diseases.