During the seventeenth century, in the wake of the discovery of the solar differential rotation, some scientists argued that stellar variability was a direct consequence of axial rotation, the spinning body showing alternately its bright (unspotted) and dark (spotted) hemispheres to the observer (Brunet 1931). Although this idea did not withstand the passage of time, it is nevertheless an interesting one because it is clearly indicative of the kind of fascination stellar rotation has aroused since its inception. And yet, at this writing there is no longer any doubt that spherically symmetric models do explain the major observed properties of stars. Moreover, if one excepts the very early and very late moments of a star's lifetime, the effects of rotation on stellar structure are apparently dynamically unimportant (e.g., Tassoul 1978, hereafter T.R.S.; Moss and Smith 1981, and references therein). What is the purpose, then, to discuss the role of rotation on the main-sequence and post-main-sequence phases of stellar evolution?