The world is awash in bullshit, and we're drowning in it. Politicians are unconstrained by facts. Science is conducted by press release. Startup culture elevates bullshit to high art. These days, calling bullshit is a noble act. Based on their popular, eponymous, course at the University of Washington, professors Carl Bergstrom and Jevin West catalogue bullshit in its many forms, explaining where bullshit arose in our evolutionary past and why it is ubiquitous today. Calling Bullshit offers readers the tools to see through the obfuscations, deliberate and careless, that dominate every realm of our lives. In this lively guide Bergstrom, a computational biologist, and West, a statistician, teach us that calling bullshit is crucial to a properly functioning social group, whether it be a circle of friends, a community of academics, or the citizenry of a nation.