How does one base their ethics on science and logic?

A friend of mine asked, "How does one base their ethics on science and logic?"

I answered,

I haven't read any of the comments yet. I am attending trainings at Landmark. I have been surprised by the transformation or in LDS terms the mighty changes of heart I have witnessed from people of other faiths and of no faith.

We are humans which means we assign right and wrong meanings to things. The agreements we have as groups, and communities are ethics. It is what we agree is right or wrong to do in general.

That is how I think science, logic and the human condition creates ethics in or outside religion.