Chapter 3: Skills and Feats
Empathy: This skill is what allows a shaman to channel her aspects. You can not take 10 or 20 with this skill.
If you have 5 or more ranks in:
Knowledge (nature): +2 synergy bonus to empathy checks made to channel Beast, Fey, Plant, or Elemental aspects.
(Will get more up as I get the aspects done)