Some logicians propose to define logical consequence on the basis of a distinction between 'logical' and 'extralogical' constants. In the first and second parts of this paper I will criticize two recent examples of this approach due respectively to Rolf George I and David Hitchcock 2 , 3. In the third part I will distinguish in my own way between logical and extralogical constants. The distinction, as understood by me, presupposes logical consequence hence cannot, on pain of vicious circularity, be appealed to in defining it. However the distinction can be enlisted without circularity in the definition of 'formal' logical consequence. My approach is motivated by the belief that for purposes of ordinary, everyday logic (what is usually called informal logic or critical thinking) there is no other useful or relevant way of drawing the distinction.