This document discusses evidential pluralism in evaluating health interventions. It argues that establishing causality requires evidence of both difference-making and mechanisms. RCTs are not necessarily better than all other evidence; mechanistic evidence is also important. A causal claim is strengthened when there is integrated evidence from different sources, such as studies showing a cause makes a difference combined with an understanding of the linking biological mechanism. The document provides categories for assessing the quality and integration of evidence from various methods regarding mechanisms and difference-making. The overall approach is not a rigid hierarchy but a more flexible evaluation of all available sources of evidence.