Is this really a post-truth world?

To rebuild belief in the power and value of truth, we can’t dodge its complexity. Truths can be and often are difficult to understand, discover, explain, verify. They are also disturbingly easy to hide, distort, abuse or twist. Often we cannot claim with any certainty to know the truth. We need to take stock of the various kinds of real and supposed truths out there and understand how to test their authenticity.

Edited extract of introduction to my new book in the Observer