Because his views of religion were deeply tied to his understanding of nature, the text's theism rests on the argument from design.

[2] The Institutes shocked and appalled many readers, primarily because it challenged basic Christian orthodoxies, such as the divinity of Christ and the miracle of the Virgin Birth.

Priestley wanted to return Christianity to its "primitive" or "pure" form by eliminating the "corruptions" which had accumulated over the centuries.

[3] Robert Schofield, Priestley's major modern biographer, describes the work as "derivative, disorganized, wordy, and repetitive, detailed, exhaustive, and devastatingly argued.

"[5] Although a few readers such as Jefferson approved of the work, it was generally harshly reviewed because of its theological positions, particularly its rejection of the Trinity.