The Benedictine Benito Jerónimo Feijoo Montenegro (Casdemiro, Orense, 1676 - Oviedo, 1764) was without doubt the most the most prominent figure of the Spanish culture in the first half of the 18th century. His work, different in style from the prose of the las Baroque period, cannot be totally included into the Enlightenment. It better belongs to that period that Paul Hazard named La Crise de la conscience européenne (1680-1715) characterized by the contradiction and confrontation of new ideas in many and diverse fields, from cosmology to the natural sciences (exposed to the reception of the new theories by Galileo and Newton), including exact sciences or the biblical critic (Richard Simon), and even philosophy (under the influence of Bacon and the post-cartesian controversy).
The discussion about these new proposals casts doubt upon certainties and visions inherited from the Middle Ages and the Renaissance that until then had been firmly accepted by the doxa. This was not only limited to society's lower strata (the concept of "the vulgar" that Feijoo applies in the first speech of his Teatro Crítico Universal is clearly strata-independent), nor was referred to those exclusively un-scholar. The project of Feijoo was not so much the systematic articulation of the new universal knowledge based on experience and reason, but the attempt to eradicate the errors admitted by the opinion of the majority. This explains the miscelaneous nature of his work that shows some similarities in styles with other works like Pseudodoxia Epidemica from the English medic Thomas Browne (1646, and many posterior editions), or even Curiosa Filosofía y cuestiones naturales (1630) from the Jesuist Nieremberg. There is no encyclopedical desire neither in Teatro Crítico Universal or the Cartas Eruditas, but only a random compilation of rebuttals to several errors. For Feijoo, truth was unique and errors were multiple and proliferating, although the sum of many in a single opinion does not guarantee its own truth.
The enterprise of Feijoo is associated with the reformism of the first Spanish Bourbons, and curiously, to the administrative, military and financial rationalization policies of the Marquis of Patiño and his collaborators. In the second half of the century, the attacks against the Benedictine increased, but also his followers within the new Enlightenment sectors. The constant opposition he found from Gregorio Mayans y Siscar was somewhat equilibrated with the support given by intellectuals and scientists of the Court (like for example, the medic and anatomist Martín Martínez). Nevertheless, the reign of Fernando VI gave way to a more fierce and ubiquitous criticism, to the point that Feijoo requested and obtained from the monarch the explicit prohibition of making public critics to his work.
Feijoo nowadays does not represent the "insufficient Enlightenment", but a transition figure corresponding to a period of time characterized by the wish to innovate in all fields of knowledge. Not only did he combat the errors contained in opinions inherited, but also created an appropriate language for the dissemination of science and public criticism, as well as he set the fundaments of the modern essay in Spanish culture.