"ranging from the 'Dictionnaire Philosophique' to Huxley's 'Essays'"
Public DomainVoltaire

These were two of the more controversial philosophical texts available at the time, and they would have been very familiar to Angel Clare.

Published in 1764, Voltaire's Dictionnaire Philosophique is a collection of articles, many of which criticise institutions such as the Roman Catholic Church.

Thomas Henry Huxley (1825-1895) was an English biologist closely associated with Darwin's theory of evolution by natural selection, which he helped promote and defend.