The Art of War

The Art of War was written between 1519 and 1520 and published the following
year, it was the only historical or political work printed during Machiavelli's
lifetime. Voltaire said, "Machiavelli taught Europe the art of war; it had long
been practiced, without being known."

— Excerpted from Wikipedia, the free encyclopedia

 "As I believe that it is possible for one to praise, without concern,
any man after he is dead since every reason and supervision for adulation is
lacking, I am not apprehensive in praising our own Cosimo Ruccelai, whose name
is never remembered by me without tears, as I have recognized in him those parts
which can be desired in a good friend among friends and in a citizen of his
country. For I do not know what pertained to him more than to spend himself
willingly, not excepting that courage of his, for his friends, and I do not know
of any enterprise that dismayed him when he knew it was for the good of his
country. And I confess freely not to have met among so many men whom I have
known and worked with, a man in whom there was a mind more fired with great and
magnificent things. Nor does one grieve with the friends of another of his
death, except for his having been born to die young unhonored within his own
home, without having been able to benefit anyone with that mind of his, for one
would know that no one could speak of him, except (to say) that a good friend
had died. It does not remain for us, however, or for anyone else who, like us,
knew him, to be able because of this to keep the faith (since deeds do not seem
to) to his laudable qualities."

— Excerpted from "The Art of War"