ROBERT FROST: THE EARLY YEARS-1874-1915 by Lawrence Thompson. 641 pages. Holt, Rinehart & Winston. $12.50.
To the millions who watched the old man recite The Gift Outright at the inauguration of John F. Kennedy, or learned to love Mending Wall or After Apple-Picking in their school days, Robert Frost was the serene, supremely benevolent country poet. A generation of interviewers had gorged themselves on his folksy humor and humble denims, on that familiar shock of untutored hair, those earthy accounts of his early scrabbling for a living from his New Hampshire poultry farm. Yet Frost also used to say: "I'm liable to...