Aristotle's Nicomachean Ethics -

Just as a knife is "good" if it cuts well, a human is "good" if they perform their unique function well.

The Path to Eudaimonia: Virtue and the Golden Mean in Aristotle’s Ethics The Ultimate End: Happiness as Flourishing Aristotle's Nicomachean Ethics

Virtue is not something we are born with; it is a developed through practice. Just as a knife is "good" if it

True happiness is not a temporary emotion but a state achieved over a complete life. The Nature of Virtue (Arete) Aristotle's Nicomachean Ethics

To be morally responsible, a person must act voluntarily and be aware of what they are doing. The Doctrine of the Golden Mean