It might seem natural to start with the assumption that everyone knows these days what dementia is. It is all around us as our populations age. Nevertheless, I shall start by setting out some basic facts about dementia. I do this not solely because there may be some who read this book without clear understanding of the medical facts about dementia, but also because the definition of ‘dementia’ is problematic. It is interesting to consider, albeit briefly, the implications of this problem, because I think they point us in two directions: towards the recognition of difference and the importance of the individual; and towards an understanding of the relevance of context. I shall then consider some of the literature that describes the neuroanatomical basis of syndromes associated with religion in the context of dementia. This neurological understanding of religion in dementia has to be set alongside the religious experience of living or working with dementia, which I shall discuss in the third section of the chapter. In the fourth, I shall suggest that some linkage between the neurological and experiential accounts of dementia might be found by considering lucid episodes, which raise profound questions about meaning and selfhood. This will lead me, in the fifth section, to discuss the importance of meaning and the broad view of personhood which can be derived from our account of meaning. In the final section, I shall discuss the implications of such a view for our understanding of religion and dementia.