UCLA School of Law

We must make policy based on realistic ideas about how machines work. In Plausible Cause, Kiel Brennan-Marquez argues first that "probable cause" is about explanation rather than probability, and second that machines cannot provide the explanations necessary to justify warrants under the Fourth Amendment. While his argument about probable cause has merit, his discussion of machines relies on a hypothetical device that obscures several flaws in the reasoning. As this response essay explains, machines and humans have different strengths, and both are capable of some form of explanation. Going forward, we must examine realistically not only where machines might fail, but also where they can improve upon the failures of a system built with human limitations in mind.