What is the test for a ratio decidendi?

In my opinion, no ratio decidendi emerges from the decision of this court in Schetky v. Cochrane that is binding on us in this case. I do not think it is either necessary or desirable, in the urgent circumstances in which this decision is required, to express any opinion on the theory that should be adopted in considering the producibility or admissibility as between the parties to a con­cluded settlement, or as between the parties to inconclusive settle­ment negotiations, of documents or other evidence arising in the course of the negotiations or setting out the terms of the settle­ment itself. The answers to those questions depend on a balancing of competing legal interests. On the one hand, anything which may tend to the finding of the truth should be brought forward. On the other hand, litigants should be encouraged to settle their differences.