This article attempts to bridge the gap between the values and skills that currently inform public health and those that we need to confront the future. We draw on a set of radical arguments. Firstly, the ability of modern people to understand, predict and control the natural world has brought many benefits but evidence is accumulating that the methods and mindsets of modernity are subject to diminishing returns and adverse effects. This is manifest in the rise of new epidemics: obesity, addiction-related harm, loss of well-being, rising rates of depression and anxiety and widening inequalities. Secondly, there is little evidence that people are embracing new forms of thinking or practice, despite other threats which have the potential for massive effects on many lives, such as climate change and peak oil. Thirdly, if the problems we face may indicate that 'modernity' is in decline because unsustainable, then profound change is necessary if we are to avoid collapse. This analysis suggests that public health needs a new approach. We set out propositions and models that could help us learn our way into the future.