Descartes: Founding Rationalism & Modern Philosophy
Descartes and Rationalism
One of the central achievements of 17th-century Rationalism was the creation of its own sphere, encompassing both reason and its method. It posited a methodical and analytical human reason, capable of understanding and transforming the world. Every thought, therefore, is an action to transform reality. Modernity sought to change everything from the past, separating itself from any authority and founding itself on the rational principles of self-knowledge. Modern science emerged to respond to this need.
The central theme became thinking itself, alongside the study of humanity and nature. This initiated a new way of thinking that sharply divided the history of philosophy. As tradition began to crumble and its epistemological assumptions lost their persuasiveness, the problem of knowledge took center stage.
With Descartes, modern philosophy took on the task of rethinking the construction of episteme from the ground up. Knowing now depended on the link between understanding and the world, but also on the conditions of the knower. Science came to be considered the most rational enterprise created by man, seeking truth and absolute knowledge.
Understanding Reality Through Mathematics
The first step was to distinguish between what things are in themselves and how we represent or imagine them to be, to question whether we know the true essence of things. Here, mathematics acquired a fundamental value, leading to the belief that nature could be translated into mathematical language.
Key Features of Cartesian Rationalism
Descartes is considered the founder of Rationalism. Its main features are:
- Full Confidence in Human Reason: Only reason, as opposed to the senses, imagination, and passion (though not necessarily opposed to faith), can lead humanity to know the truth. Its power lies in the ability to grasp the first truths themselves and base them on innate ideas, from which, by deduction, all others can be derived. A deductive chain of the world system can be built. Reason is a faculty systematic and consistent with reality, as Parmenides believed when he equated thinking and being. Reason is accepted without prior criticism; it is a dogmatic reason, something that Kant would later denounce.
- Finding a New Method: The next step, after recognizing the value of reason, is to find a suitable method of reasoning, contrary to the dispersion of the early Renaissance. The model is the method of mathematical discovery, intended to proceed with the evidence and necessity of mathematics. There is no further discussion about intuition itself, but rather on how to achieve it, to avoid uncertainty and error.
Descartes’ Philosophical Project
Descartes intended to undertake the construction of a philosophy that was firm, secure, lasting, and true. The history of philosophy is presented as an endless succession of views. From the division made by Aristotle of the powers of the soul (external senses, common sense, understanding, memory, and imagination), Descartes explains how humans can achieve objectivity.
All powers, except understanding, operate by virtue of the soul and body, so the cause of error stems from the senses and imagination. Thus, he disregards experience as a starting point. Purified and rid of the senses, he advocates for the use of pure reason confined to itself: starting from the idea to reach the reality of the thing.