For example, Descartes and John Locke, one of the most important Enlightenment thinkers, have similar views about the nature of human ideas. How can we be sure that these objects do not appear one way before the mind and exist in another way or not at all in reality outside the mind?
The collaborative nature of the project, especially in the context of state opposition, contributes significantly to the formation of a shared sense of purpose among the wide variety of intellectuals who belong to the French Enlightenment.
Even as he draws strict limits to rational knowledge, he attempts to defend reason as a faculty of knowledge, as playing a necessary role in natural science, in the face of skeptical challenges that reason faces in the period.
But if our conception of nature is of an exclusively material domain governed by deterministic, mechanical laws, and if we at the same time deny the place of the supernatural in the cosmos, then how does humanity itself fit into the cosmos? Thus, the Enlightenment became critical, reforming, and eventually revolutionary.
In the Treatise on SensationsCondillac attempts to explain how all human knowledge arises out of sense experience. This shift can also be seen in gardening : French gardens were less controlled, more spontaneous than British gardens for example.
While rationalism, as the view that reason is the main source of knowledge, did not dominate the Enlightenment, it laid critical basis for the debates that developed over the course of the 18th century. Some philosophers today, most notably John Cottingham, note that rationalism, a methodology, became socially conflated with atheism, a worldview.
If one denies that there is disorder and evil in nature, however implausibly, the effect is to emphasize again the dissimilarity between nature and human products and thus weaken the central basis of the argument.
According to Locke, in order to understand the nature and source of legitimate political authority, we have to understand our relations in the state of nature. Locke defines the state of nature as a condition in which humans are rational and follow natural law, in which all men are born equal and with the right to life, liberty and property.
Amid the turmoil of empire, however, a new concern arose for personal salvationand the way was paved for the triumph of the Christian religion. The political philosopher Montesquieu introduced the idea of a separation of powers in a government, a concept which was enthusiastically adopted by the authors of the United States Constitution.