Harvey addresses the issue of forgiveness and moving forward after a relationship setback by emphasizing the importance of self-reflection, acceptance, and growth. He encourages individuals to forgive themselves and others involved in the setback, acknowledge the valuable lessons learned from the experience, and focus on personal development and healing to move forward in a positive direction. Harvey also emphasizes the significance of setting boundaries, practicing self-care, and surrounding oneself with supportive relationships to aid in the process of forgiveness and moving on after a relationship setback.