Love and Wisdom
Love and wisdom need one another to function. Without wisdom, someone with love has no framework for doing things which will actually improve the lives of others. A doctor with poor knowledge of the human body may prescribe a drug that does more harm than good, and a politician without economic knowledge may write a law that causes economic damage, even if it sounded like a good idea. Science can give us knowledge that we can use to improve our actions. It gives us the tools to improve our lives and the lives of others, but a tool must be wielded with purpose.
Update: What I mean by this is that intentions alone never give the moral high ground. It is a moral duty to think through the consequences of your actions, at least in proportion to the likely impact on the world. The road to hell is paved with good intentions.