Integration in medical education is often misunderstood. This is despite the fact that it is frequently seen as being a key idea to providing a medical education that will adequately prepare students for the world of modern medical practice. Integration is an idea with complex nuances and, unfortunately, those nuances often go unappreciated by many medical educators. If integration really is important then medical educators need to inform themselves of the nuances and the different levels of complexity involved. In this commentary, I provide an overview of some of that complexity. The main message is that we need an interdisciplinary approach to understanding integration. To fully understand what integration involves then we ourselves, as educators, need to integrate insights from a range of theoretical lenses. First, we consider integration at the curriculum level and then move on to integration at the level of the individual student and practitioner. One discipline that helps us understand integration is history.