His political position is often compared with that of Thomas Hobbes, but there are also clear differences; he was also called in his time a Latitudinarian, but this is not something on which modern scholars are agreed.
[1] After the Restoration, his views met the disapproval of the warden of Wadham, Walter Blandford, and he migrated to Trinity College, where he proceeded MA 9 July 1663.
[4] In 1665 he published an essay entitled Tentamina physico-theologica de Deo, dedicated to Archbishop Gilbert Sheldon, who in 1667 appointed him one of his chaplains.
In fact the Free and Impartial Censure took wide aim at hermetic thinkers in general, such as Rosicrucians, Thomas Vaughan and John Heydon.
[9] The aim of the book was, 'by representing the palpable inconsistency of fanatique tempers and principles with the welfare and security of government, to awaken Authority to beware of its worst and most dangerous enemies, and to force them to that modesty and obedience by severity of Laws to which all the strength of Reason in the world can never persuade them.'
In A Demonstration of the Divine Authority of the Law of Nature (1681) Parker developed earlier work, and also adapted arguments from the De legibus naturae (1672) of Richard Cumberland.
In 1687 the Ecclesiastical Commission forcibly installed Parker as president of Magdalen College, Oxford, the fellows having refused to elect any of the king's nominees.
When, after the death of Henry Clerke, President of Magdalen, Thomas Smith called upon him to canvass support, he replied that 'the king expected that the person he recommended should be favourable to his religion.'
Six months later, after the failure of his attempt to force Anthony Farmer upon the fellows, the king nominated Parker himself as President of Magdalen College (14 August 1687).
[2] On 2 November he came into residence, and during the next four months admitted Catholic Fellows and demies, including several Jesuits, on successive mandates from the king.