(A ruler) cannot and should not keep his word when to do so would go against his interests or when the reason he pledged it no longer holds.

No proceeding is better than that which you have concealed from the enemy until the time you have executed it. To know how to recognize an opportunity in war, and take it, benefits you more than anything else. Nature creates few men brave, industry and training makes many. Discipline in war counts more than fury.

He who is the cause of another's advancement is thereby the cause of his own ruin.

...it behooves us to adapt oneself to the times if one wants to enjoy continued good fortune.

There is nothing as likely to succeed as what the enemy believes you cannot attempt.

Few men are brave by nature, but good discipline and experience make many so.

And when he is obliged to take the life of any one, to do so when there is a proper justification and manifest reason for it; but above all he must abstain from taking the property of others, for men forget more easily the death of their father than the loss of their patrimony.