Priestley’s energies were, however, not wholly engrossed by his scientific labours. Theology and metaphysics still claimed much of his time, and to this period belongs the concluding portion of his _Institutes of Natural and Revealed Religion_ and his _Harmony of the Gospels_, and his _Disquisitions relating to Matter and Spirit_. He also at this time wrote some _Miscellaneous Observations relating to Education_, and published his Warrington _Lectures on Oratory and Criticism_, which he dedicated to his patron’s eldest son, Lord Fitzmaurice. Certain of these publications occasioned considerable uproar at the time of their appearance: the outcry indeed was such, he says, as could hardly have been imagined. He was attacked in almost every newspaper, and in the greater number of the periodicals, as an unbeliever in revelation and no better than an Atheist. In the preface to his _Institutes of Natural and Revealed Religion_ he had been led to question the principles of Reid, Beattie and Oswald with respect to their doctrine of _common sense_, which they had made to supersede all rational inquiry into the subject of religion, and he subsequently developed the attack in a separate publication. He expressed his belief in the doctrine of philosophical necessity and his admiration of Hartley’s theory of the human mind. He had uttered some doubt of the immateriality of the sentient principle in man, and after giving, as he says, the closest attention to the subject, he was firmly persuaded that man is wholly material, and that our only prospect of immortality is from the Christian doctrine of a resurrection. Priestley clearly recognised that many of these publications were not calculated to improve his relations with Lord Shelburne. Indeed, he says several attempts were made by Lord Shelburne’s friends, though none by himself, to dissuade him from persisting in them. He goes on to say that:— “In order to proceed with the greatest caution in a business of such moment I desired some of my learned friends, and especially Dr Price, to peruse the work before it was published, and the remarks that he made upon it led to a free and friendly discussion of the several subjects of it, which are afterwards published jointly, and it remains a proof of the possibility of discussing subjects mutually considered as of the greatest importance with the most perfect good-temper and without the least diminution of friendship.” Lord Shelburne’s political enemies were not slow to take advantage of the outcry raised against Priestley by the orthodox and to strike at the patron through the philosopher.