"The Heart Of The Matter" is the fourth episode of the fourth season of Grey's Anatomy and the 65th produced episode of the series. It is also the 69th produced episode of the Grey's Anatomy franchise. It was broadcast on October 18, 2007.
In the wake of the breakdown of their marriage, Callie and Izzie face off while George is stunned when Callie agrees to forgive him while Izzie confides in Alex about her affair and get a very unexpected reaction. Derek propositions Meredith about their future together while Derek teaches Cristina a lesson when he notices her mistreatment of Lexie and her interns. Richard's neice returns to the hospital with Adele.
- "In life only one thing is certain, apart from death and taxes: No matter how hard you try, no matter how good your intentions, you are going to make mistakes. You are going to hurt people. You are going to get hurt. And if you ever want to recover, theres really only one thing you can say..."
- "Forgive and forget. That's what they say. It's good advice, but it's not very practical. When someone hurts us, we want to hurt them back. When someone wrongs us, we want to be right. Without forgiveness old scores never settle. Old wounds never heal, and the most we can hope for is that someday we'll be lucky enough to forget."
- "Better Already" - Northern State
- "Milk And Honey" - Price Fatty
- "The Absence Of Your Company" - Kim Richey
- "Rockers To Swallow" - Yeah Yeah Yeahs
- "Hawaii" - Meiko
- "Sun Comes Up" - Jon Legend
This episodes' title references the song The Heart Of The Matter, originally sung by Don Henley