Some of today's discussion is reviewed in these notes here; you can apply what's said there to our current issuess:

http://ethicsandanimals.googlepages.com/lectures.htm#_Lecture_1:_Introduction

See esp.:

• What the Question Is Not: Not “Morally Right,” but Morally Permissible and/or Morally Obligatory
• Some Basic Concepts about Arguments: Introduction to Logic
• Moral Principles as Premises: Introduction to Ethics
• Religion and Ethics: A Brief Comment