How did the ideas of the Renaissance, Reformation, and Scientific Revolution affect the Enlightenment?
The Enlightenment was an extension of many of the ideas of the Renaissance and Reformation.
The first element of this is religious. The Reformation and the rise of Protestantism broke the stranglehold of the Roman Catholic Church on Europe. Protestantism was inherently anti-clerical, arguing for the importance of Scripture and personal faith in salvation, rather than insisting that salvation was exclusively mediated by Church ritual and hierarchy. This led to pressure for increased freedom of religion and emphasis on personal conscience, something that was increasingly important in the Enlightenment.
In studying classical and religious texts, the Renaissance and Reformation were associated with a return "ad fontes" (to the origins), which meant seeking early manuscripts and studying them in historical context in their original languages. This led to the scientific, historical, and philological studies of the Enlightenment and the rise of altertumswissenschaft (the science of antiquity).
The Renaissance admiration of ancient Rome led to interest in the Roman Republic as a political model, something that led to the movement for democracy in the Enlightenment. The early modern period was the beginning of the rise of the bourgeoisie.
The Renaissance, in casting off scholasticism, marked the beginning of modern science. Modern science was grounded in reason, observation, and experiment, as found in such figures as Bacon, Copernicus, and Galileo. These scientific advances led to the expansion of science in the Enlightenment and the application of scientific method to humanistic, social, and political issues.
The Renaissance and Scientific Revolution contributed heavily to Enlightenment ideas. The influence of the Reformation was not so great, in fact some reformation thinkers disagreed with Enlightenment ideas.
The Renaissance and Scientific Revolution had challenged the Medieval concept of scholasticism, in which one accepted authority without question. That "authority" included the concept of a geocentric universe, Experimentation was considered dangerous, as it might lead one to error, and error to sin, and sin to damnation. Renaissance thinkers were perhaps the first to question Scholasticism and explore the concept of a rational universe. This idea was further explored during the Scientific Revolution when scholars argued that the entire universe could be proven by mathematical principles. It is here that the first conflict with Reformation thinkers became apparent. In response to Copernicus' theory that the solar system was heliocentric, Martin Luther called Copernicus:
the new astrologer who wants to prove that the earth moves and goes round….This fool wants to turn the whole art of astronomy upside down
In summary, the Enlightenment is normally considered by scholars to be the natural conclusion of the Renaissance, since both were secular in their approaches. The only explanations accepted were those which were reasonable and "worldly." It was further a continuation of a process which began with the Scientific Revolution. From that revolution, a new way of thinking about science, nature, and humanity had developed. That way of thinking was the nativity of the Enlightenment.