1. A Guilty Conscience: This is the most direct opposite, where one feels remorse, shame, and regret for past actions.
2. A Troubled Conscience: This implies a state of inner conflict or unease about something, even if it's not necessarily a specific wrongdoing. It's a sense of being troubled or burdened by something.
3. A Callous Conscience: This describes a lack of sensitivity to right and wrong, a disregard for moral principles, and an absence of remorse.
4. A Hardened Conscience: This implies a conscience that has become insensitive through repeated wrong actions. It's a conscience that has become resistant to feelings of guilt or remorse.
5. A Stained Conscience: This is a metaphorical way of describing a conscience that has been affected by past wrongdoings, leaving a lasting mark on the individual's sense of right and wrong.
The best word to use will depend on the specific context and the nature of the individual's inner state.