Archibald Campbell, 3rd Duke of Argyll and 1st Earl of Ilay, lived a long and very active life as soldier, lawyer, politician, patron and businessman. History remembers him on the one-hand as courageous, good-natured, learned and accomplished - and, on the other, as 'a man of little truth, little honour, little principle'. His substantial political career, driven by gaining and increasing his power and that of his friends, is poorly documented, since many of his private papers have vanished. The author's interest in Argyll as a key figure in the Scottish Enlightenment - which became a thirty-year-long quest to piece together the fragmentary evidence of his complex life into a coherent story of the contradictions within his personal, intellectual and business activities - has given us the first major study of a fascinating man, shown as having changed the nature of Scottish culture.