If you're looking for a couple of slim volumes to read on your travels this summer, look no further. Here are two books to divert, improve, and inform. Firstly, Testing Treatments by Imogen Evans, Hazel Thornton, and Iain Chalmers is, according to our reviewer Ike Iheanacho, “a terrific little book” (p 1516). Its premise is that “knowledgeable ignorance” is something to aspire to. We should embrace uncertainty and stop feeling that we need to pretend that we know all the answers. Instead, say the authors, we should be rigorously questioning whether what we and others do is truly effective, since logic and good intentions are not enough. Sure …