Palmer, Donald. Why it’s hard to be good : an introduction to ethical theory / text and illustrations by Donald Palmer. - Boston : McGraw-Hill, c2006 - x, 422 p. : ill. ; 24cm. Includes bibliographical references (p. 390-392) and index ISBN: 0767424093 9780767424097 Subjects--Topical Terms: Ethics--History. Subjects--Index Terms: Đạo đức Lịch sử Lý thuyết đạo đức Dewey Class. No.: 171