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.
When a house is tottering to its fall,
The strain lies heaviest on the weakest part,
One tiny crack throughout the structure spreads,
And its own weight soon brings it toppling down.
In your judgment virtue requires no reward, and is to be sought for itself, unaccompanied by external benefits.
[Lat., Judice te mercede caret, per seque petenda est
Externis virtus incomitata bonis.]