Cunning leads to knavery. It is but a step from one to the other, and that very slippery. Only lying makes the difference; add that to cunning, and it is knavery.
The raven once in snowy plumes was drest,
White as the whitest dove's unsullied breast,
Fair as the guardian of the Capitol,
Soft as the swan; a large and lovely fowl
His tongue, his prating tongue had changed him quite
To sooty blackness from the purest white.