It is time someone exploded the myth of "summer doldrums," the canard that every right-thinking American is unconcious in a hammock. Consider the unfathomable stirrings of the restless human mind. Is it any less restless in summer than in winter? Certainly not. Jean Shepherd, an all-night disk jockey (WOR), has been spending his hours defending "night people," who, he argues, are more creative than stodgy, schedule bound "day people." He has been propounding the thesis that night people are being persecuted by "official, organized. Righteous day people" who are completely bound by their switchboards and red tape, timetables, and official lists. As an instance of this, Shepherd recently said he had tried to buy a copy of an old book only to be told by a day-person book clerk that it did not exist 'because it was not on his official publishers' list. Shepherd urged the night people to retaliate by asking book clerks for a book that was really non-existent and urgedthem to send in titles for it. Among several thousand he finally picked "I, Libertine," ascribing it to "non-author than" Frederick R. Ewing, for whom he concocted an impressive career - a former Manchester Guardian correspondent, an ex-BBC commentator on "Erotica of the 18th Century," and wartime commander of a minesweeper in the North Atlantic. So many of Shepherd's night people began asking for this book that day-people clerks began pestering salesmen for it, the salesmen in turn pestered their publishers and finally Publisher Ian Ballantine saw the light of opportunity and is now actually publishing a book to be called "I, Libertine," by Frederick Ewing, with the assistance of Jean Shepherd.