If your head tells you one thing and your heart tells you another, before you do anything, you should first decide whether you have a better head or a better heart.
- Marilyn vos Savant (1946- present)
If you judge with your heart, you will judge emotionally. If you judge with your head, you will judge practically. Say you are a missionary. Your heart will say "I should do this! Spread God's word, help the people, etc." However, your head would tell you "You know, this is great and all, but I could get arrested..." If someone wrongs you, your heart would (should) say "this person deserves a second chance," but your head would say "if I give them the chance to, they will wrong me again."