  Lewis’s definition of convention demands complete or near-complete conformity. Many commentators object that this is too strict, excluding conventions “more honored in the breach than the observance.” To take Margaret Gilbert’s example (1989), there might be a convention in my social circle of sending thank-you notes after a dinner party, even though few people actually observe this convention anymore. Lewis must deny that sending thank-you notes is a convention, a verdict which Gilbert and other commentators find unintuitive. Wayne Davis (2003) and Ruth Millikan (2005) develop similar objections.