Samuel Clarke was an English philosopher and Anglican cleric. He is considered the major British figure in philosophy between John Locke and George Berkeley. Clarke's altered, Nontrinitarian revision of the 1662 Book of Common Prayer continues to influence worship among modern Unitarians.

George Berkeley – known as Bishop Berkeley – was an Anglo-Irish philosopher whose primary achievement was the advancement of a theory he called "immaterialism". This theory denies the existence of material substance and instead contends that familiar objects like tables and chairs are ideas perceived by the mind and, as a result, cannot exist without being perceived. Berkeley is also known for his critique of abstraction, an important premise in his argument for immaterialism.