Just to add something else here.

As a Mason, Burns would subscribe to the concept of the Great Architect of the Universe as the overriding "power" so I would have to disagree with Robertson on this point seen from Burns' own point of view. Something beyond the power of man.

Science doesn't quite fit the bill here nor Nature as such.

Going back to my original citation, nature does not "mak mankind your care" which indicates something more personal.

But of course it's a point we can debate o'er a wee dram next week!