'then one might mention the old roman legend about the books of the sibyl that contained mysterious information direct from the gods - 'in other words , gentlemen , while you are right that any change in the course of past events , however trifling , would have incalculable consequences , and while i also believe that you are right in supposing that any random change is much more likely to be for the worse than for the better , i must point out that you are nevertheless wrong in your final conclusions .