Does the "Unified Theory" skill feat have any interaction with the "Natural Medicine" skill feat?

Question

The Unified Theory skill feat states that:

Whenever you use an action or a skill feat that requires a Nature, Occultism, or Religion check, depending on the magic tradition, you can use Arcana instead.

The Natural Medicine skill feat states that:

You can use Nature instead of Medicine to Treat Wounds.

One interpretation is using Arcana in place of Nature check to Treat Wounds, because it is a skill feat that requires a Nature check.

Another interpretation is requiring the action's or skill feat's Nature check to have something to do with the Primal tradition of magic, since there is line "depending on the magic tradition".

Finally, there are traits for "Arcane" "Divine" "Occult" "Divine" and "Magical". If they really wanted to limit the Unified Theory skill feat to only work in those specific cases, there were ways to do that clearly and mechanically.

How would you run it? Is there a definite answer?

Answer 1

There is no interaction

Unified Theory has three requirements:

1. That you are using an action or skill feat.
2. That whatever you are doing requires a Nature, Occultism, or Religion check.
3. That the kind of check is determined by a magical tradition.

Using Nature to Treat Wounds passes the first two conditions, but not the third. Therefore, you cannot use Unified Theory to replace the check with Arcana.

This reasoning also applies to other kinds of checks covered by these skills. For example, you can't use Unified Theory to attempt an Arcana check to issue commands to an animal as described in the Nature skill.

You had asked for a "definitive" answer. I'm not sure there is an official source or ruling to cite, but the requirement that the kind of check be determined by a magical tradition is explicitly included in the text of the feat.