  Stability analysis on the De Sitter universe in pure gravity theory is known
to be useful in many aspects. We first show how to complete the proof of an
earlier argument based on a redundant field equation. It is shown further that
the stability condition applies to $k \ne 0$ Friedmann-Robertson-Walker spaces
based on the non-redundant Friedmann equation derived from a simple effective
Lagrangian. We show how to derive this expression for the Friedmann equation of
pure gravity theory. This expression is also generalized to include scalar
field interactions.
