Focussing on the two most interesting and productive periods of his life, the years spent at Oxford (1653-7, possibly 1661) and in London as Chaplain to the Lord Keeper of the Beal, Sir Orlando Bridgeman, (1669-1674), this study analyses Traherne's published and unpublished writings in relation to specific aspects of the contemporary world from which they issue and to which they relate. The vigorous expatiation achieved in Traherne's prose and the intellectual ambitions revealed in his notebooks reflect an insatiable capacity for knowledge and experience. He rejects what he is aware of as the world of "Invention" only in order to idealise the world of "Nature". It is through observation and understanding ("Enjoyment") of this, the physical world, that "Felicity" is sought. This doctrine includes "Practical Happiness" and seeks fulfilment in "Perfect Life" in all senses in the "true Estate of this World". The rejection of the world of invention can be seen as a conscious reaction against "the Customs and Maters of Men" in a society in which the theories of Hobbes, for example, had serious ideological purchase. As a younger contemporary of Pepys and Dryden, Traherne can be seen in relation to the society in which they too lived and wrote. As Chaplain to the holder of the highest state office in Charles II's government he has a natural place in Restoration London. He suggests that he was "admitted to the society and friendship of Great Men". His patron Bridgeman was associated, through his involvement with the Comprehension Bill of 1668, with the Duke of Buckingham and John Wilkins, among others. Burnet suggests that Andrew Marvell can be associated with the cause that Bridgeman sought to promote. In 1673 when, as Burnet observes, "Popery was everywhere preached against", Traherne published Roman Forgeries, an attempt to discredit the authority of the Roman Catholic church. Traherne expressed particular interest in "Natural Philosophy". This contributes to "Felicity" through "Enjoyment" of God's creation and the "Thanksgiving" that issues from this". The Webster-Ward Debate and the meetings of John Wilkins' experimental philosophy club in Oxford in the 1650's suggest Traherne's proximity to an increasingly significant pursuit. The Early Notebook shows that Traherne read Bacon's De Aus~aantis Scientiarum at this time. His later writing is haunted by images reflecting preoccupations of contemporary natural philosophy, and his "Divine Philosophy" celebrates the "Common Things" of the physical world. In London the Bridgeman household lived at Essex House in the Strand when the Royal Society was meeting in the neighbouring Arundel House. Richard Cumberland, in a book dedicated to Bridgeman in 1672, describes the Society's "Natural Philosovhy" in such a way as to suggest close correspondence between this and Traherne's "Divine Philosophy". Thomas Sprat's The History of the Royal Society (1667) and other works by contemporary natural philosophers, particularly Robert Boyle, emphasize this. As for Traherne, "Felicity" is achieved through "contemplation of God's Works", so, for Sprat and the Royal Society, "contemplation of God's visible Works" leads man to millenial fulfilment. In this study, analysis of the notebooks and their sources, and of aspects of the contemporary milieu from which they and the prose writings issue and to which they relate, is complemented by an exploration of each of the prose writings in an attempt to show the extent and seriousness of Traherne's purpose and his intellectual accomplishment as a major writer of the Restoration period.