Recently I wrote a post about the Global Evidence Summit, which I attended in September. I commented that one thing I really liked about the conference is that it had some great plenary sessions. In this post, I highlight some of the key ideas that came from the fourth plenary of the conference, titled “Evidence in a Post-Truth World.”
The plenary started with Trish Greenhalgh, who is a Professor of Primary Care Health Sciences at the University of Oxford. Greenhalgh’s bio for the conference lists three areas her work covers, one of which is the complex links (philosophical and empirical) between research, policy and practice. Her speech focused on these philosophical links. She started with Aristotle’s On Rhetoric, in which he lays out three means of persuasion for an orator. The first is logos, which we can think of as evidence. The second is ethos, which we can think of as credibility, and the third is pathos, which we can think of as emotion. Greenhalgh suggested that the post-truth world is one where logos – evidence – is no longer a useful tool of persuasion, leaving us only with the other two.