Had it not been for this trifle from Moschus in the _Alastor_ volume, and the passage in Shelley’s letter (dated to Hogg from ‘Bishopgate, September, 1815’), where he says, ‘I have been engaged lately in the commencement of several literary plans which, if my present temper of mind endures, I shall probably complete in the winter,’ it would probably never have occurred to any editor of Shelleyan MSS. that Shelley produced, in 1815, a composition so foreign to his way of dealing with religious questions at any time, between the publication of _The Necessity of Atheism_ and the production of _Laon and Cythna_, as the fragmentary treatise on the character and teaching of the Saviour of the World. It is not far to seek how the editorial mind came to commit so strange a mistake. On the discovery amongst Leigh Hunt’s MSS. of the beginning of a translation of Moschus’s third idyll (the elegy on Bion), written by Shelley on the same paper as a missing piece of the _Essay on Christianity_, it became obvious that the _Essay_ was written at a time when he was interested in the writings of Moschus. This being manifest the first of the misleading editors argued thus: The _Essay on Christianity_ was written near the time when Shelley was working at Moschus; the _Alastor_ volume which passed through the press soon after the composition of the poem in the autumn and winter of 1815, contains a translation from the Greek of Moschus, showing that somewhere about that time the poet was interested in the Moschian idylls; moreover we have Shelley’s assurance that in September, 1815, he was engaged on several literary enterprises which he hoped to complete in the course of the ensuing winter. Therefore one may safely assign the fragmentary _Essay on Christianity_ to the year 1815.