Thomas Edison is often celebrated as one of the greatest inventors in history, but a closer look reveals that some of his actions were ethically questionable, sometimes cruel, and occasionally dangerous.
Below are several of the more troubling aspects of Edison’s career, drawn from historical research and analysis.
The “War of the Currents” Campaign Against AC
Edison was a strong proponent of direct current (DC) electricity, and he viewed alternating current (AC), championed by George Westinghouse and Nikola Tesla, as a threat to his business.
In the effort to discredit AC, Edison conducted demonstrations that many now regard as cruel. He arranged for animals, dogs, cats, cattle, and horses, to be electrocuted using AC power in public displays to show how dangerous AC was.
These acts were intended to influence public opinion, legislators, and regulators, rather than simply to advance scientific understanding. Critics argue these campaigns were essentially fear tactics and involved suffering and death in animals for competitive gain.
Edison Electrocuted Topsy the Elephant
One of the most notorious events tied to Edison (or at least to his company) is the execution of Topsy, a circus elephant at Luna Park, Coney Island, in January 1903. Topsy had killed several handlers over time, and park authorities decided she must be put down.
The method chosen involved electrocution with AC, which was filmed by Edison’s company, served publicly as both entertainment and a demonstration.
The event is often presented as part of Edison’s anti‑AC campaign, although historical investigation suggests his personal role may have been less direct. Still, the spectacle of killing a large animal, apparently partly for effect, remains deeply disturbing in retrospect.
His Experiment Killed His Assistant, Clarence Dally
When X‑rays were newly discovered, Edison and his lab assistants experimented with them without understanding their risks.
His assistant Clarence Madison Dally suffered severe injuries during these experiments: lesions to hands and face, contentions of radiation burns, eventual amputations, and finally death from cancer related to radiation exposure.
Edison reportedly tried to warn of danger once effects became clear, but only after Dally had already been harmed significantly.
For some, Dally’s suffering is a tragic example of the human cost of early scientific experimentation and of Edison’s drive to experiment even when safety wasn’t well understood.
The Way He Treated Other Inventors
Edison’s relationship with patents, other inventors, competitors, and recognition has been controversial. One such case involves Granville Woods, a Black inventor who developed important inventions in telegraphy and electrical communication.
Woods faced lawsuits from Edison over claims that Edison had invented similar technologies first. Historians have noted that Edison often sued competitors, or used legal and business pressure, to defend his market position.
Some documents suggest that Edison may have tried to take credit, or at least advantage, over the work or inventions of others.
While in many cases the courts or patent offices resolved such disputes, the aggressive legal strategy and the imbalance of power (wealth, equipment, connections) often favored Edison.
He Was Not a Good Human Being
Edison’s marketing, public relations campaigns, and business methods were sometimes ruthless. His “smear tactics” against AC involved shows of electrocution for shock value.
He invested in legal efforts to block competitors via patents, sometimes trying to monopolize parts of the motion picture industry through patent controls.
For example, via the Motion Picture Patents Company, which many historians view as an attempt to limit competition and stifle smaller creators.
In these activities, the ethical line between innovation, competition, and exploitation becomes blurry to Thomas Edison.
