A Special Issue of this journal, edited by Lynch et al., was published critiquing research in conversation analysis on epistemics and on oh. It would be more accurate to say that the articles in that Special Issue critique the work of Heritage on epistemics and oh. Their principal criticism is that Heritage’s analyses of epistemics and oh are cognitivist. Other criticisms are that his analysis of each of these phenomena is not sequential, that it does not attend to the details (...) of turn design, and that his analyses are not truly conversation analytic – indeed that he does not comprehend CA, that his analyses are false and unwarranted, that he has adopted an ‘informationist’ perspective of knowledge transfer, and that epistemics represents some ‘hidden order’ invisible at the surface of conversation. Underlying these criticisms is their contention that Heritage has not adhered to the ‘radical’ agenda of ethnomethodology which, they claim, underlies the origins of CA. In this Introduction, I outline some of the principal reasons for regarding the criticisms in The epistemics of Epistemics to be misguided, inaccurate and scurrilous. In doing so, I am setting out in very broad outline the arguments made by the contributors to this Special Issue rebutting those criticisms of Heritage’s work, and of CA more generally. (shrink)