Grace Davie is a professor of sociology at the University of Exeter, the United Kingdom. Her research interests lie in the sociology of religion, with a particular emphasis on patterns of religion in Europe. She is also interested in the new theoretical paradigms that are emerging in the field – not least the notion of “multiple modernities.” This lecture reflects on the notion of non-belief from two rather different perspectives: first the conceptual and then the comparative. The first section looks at different understandings of non-belief and their relationships to other dimensions of religious/ non-religious life. Such connections are not always self-evident. The second section introduces a comparative dimension in order to demonstrate that – just like belief or religion itself – non-belief varies considerably across contexts. The question is approached using both quantitative and qualitative examples taken from different parts of Europe. What emerges overall is a spectrum (or rather spectrums) rather than a typology of unbelief. A short postscript introduces the global dimension: it deepens the conceptual enquiry, expands the comparative perspective, and reminds us that the unexpected can and does happen.