Wisdom is not wisdom when it is derived from books alone.
For, once begun, Your task is easy; half the work is done.
You must avoid sloth, that wicked siren.
Faults are committed within the walls of Troy and also without. [There is fault on both sides.]
Our parents, worse than our grandparents, gave birth to us who are worse than they, and we shall in our turn bear offspring still more evil.
Consider well what your strength is equal to, and what exceeds your ability.