"Whoever has witnessed another's ideal becomes his inexorable judge and as it were his evil conscience"

This quote by Friedrich Nietzsche suggests that when someone observes another person's strong belief or goal, they end up being liable for their own actions and are evaluated by that belief. The person's perfect ends up being a representation of their morals and principles, and if they stop working to measure up to it, they will be reminded of their failure like an inner voice or "wicked conscience."