This paper focuses on the contributions to natural history, particularly in methods of plant classification of the Portuguese botanist, man of letters, diplomat, and Freemason Abbé José Correia da Serra (1751-1823), placing them in their national and international political and social contexts. Correia da Serra adopted the natural method of classification championed by the Frenchman Antoine-Laurent de Jussieu, and introduced refinements of his own that owe much to parallel developments in zoology. He endorsed the view that the classification of plants (...) should be based on the establishment of affinities rather than of differences. The emphasis on affinities went hand in hand with the development of the concept of symmetry. This idea was introduced by Correia da Serra in systematics and was adopted and further developed by his friend, Augustin-Pyramus de Candolle. Correia da Serra also argued that Cryptogamia reproduce sexually, advocated extension of methods of comparative anatomy from zoology to botany, and applied them to the study of fruits. Correia da Serra was one among many of the estrangeirados, Portuguese "Europeanized" intellectuals who traveled extensively abroad in most cases to escape political or religious persecution at home. The estrangeirados were important contributors to 18th and 19th century European thinking. Most of the estrangeirados were pivotal in the introduction, dissemination and propagation of the new sciences in Portugal, but unlike most of his fellow estrangeirados, Correia da Serra was also an innovative man of science in his own right. (shrink)