It may easily be conceived that Napoleon wished to give to the documents which he knew historians would consult a favourable colour, and to direct, according to his own views, the judgment of posterity on his actions: But it is only by the impartial comparison of periods, positions, and age that a well founded decision will be given. About his fortieth year the physical constitution of Napoleon sustained considerable change; and it may be presumed that his moral qualities were affected by that change. It is particularly important not to lose sight of the premature decay of his health, which, perhaps, did not permit him always to, possess the vigour of memory otherwise consistent enough with his age. The state of our organisation often modifies our recollections, our feelings, our manner of viewing objects, and the impressions we receive. This will be taken into consideration by judicious and thinking men; and for them I write.
What M. de Las Casas states Napoleon to have said in May 1816 on the manner of writing his history corroborates the opinion I have expressed. It proves that all the facts and observations he communicated or dictated were meant to serve as materials. We learn from the Memorial that M. de Las Casas wrote daily, and that the manuscript was read over by Napoleon, who often made corrections with his own hand. The idea of a journal pleased him greatly. He fancied it would be a work of which the world could afford no other example. But there are passages in which the order of events is deranged; in others facts are misrepresented and erroneous assertions are made, I apprehend, not altogether involuntarily.
I have paid particular attention to all that has been published by the noble participators of the imperial captivity. Nothing, however, could induce me to change a word in these Memoirs, because nothing could take from me my conviction of the truth of what I personally heard and saw. It will be found that Napoleon in his private conversations often confirms what I state; but we sometimes differ, and the public must judge between us. However, I must here make one observation.