Descartes’ Methodical Doubt and the Search for Truth
1.2 The Key to Understanding the Cartesian Method
Scholasticism Crisis
René Descartes (1637) is considered a cornerstone of modern philosophy. After the Middle Ages, which hadn’t produced any truly original philosophical doctrines, rationalism took on a new edge with Descartes’ approach. Several factors contributed to this shift:
- Nominalism, with figures like William of Ockham, challenged scholasticism from within.
- Renaissance humanism encouraged a return to classical antiquity.
- The new science introduced new methods and theories, clashing with the established scholastic education system in universities.
Scholasticism faced two main objections:
- The criterion of truth: Scholasticism relied on faith and authority. How could one know if an issue was true or false without independent verification?
- The method: The Aristotelian syllogism, while logically sound, only worked if the initial premises were true. How could the truth of these premises be established? Furthermore, the syllogistic method seemed to reinforce dogma, preventing new discoveries.
Scientific Revolution
The scientific revolution, with figures like Copernicus, Kepler, and Galileo, offered new methods and theories. The idea that nature could be understood through mathematical formulas and proportions resonated with Descartes. However, he was critical of the emphasis on observation and experiment.
The Impact of Skepticism
Renaissance skepticism, with its emphasis on universal doubt, posed a significant challenge. Descartes saw skepticism as a valuable tool for clearing away preconceived notions, but he also recognized the danger of succumbing to complete doubt. He aimed to use skepticism to arrive at certain and unshakeable knowledge.
1.3 The Search for a Criterion of Truth: Methodical Doubt
What is Methodical Doubt and What are its Goals?
Descartes’ methodical doubt aimed to establish a firm foundation for knowledge. By systematically doubting everything, he hoped to find principles that were immune to skepticism. This involved rejecting any belief that could be doubted, no matter how small the doubt.
How is it Done?
Descartes’ doubt was systematic. He began by doubting sensory information, as our senses can be deceiving. He then questioned the distinction between waking and dreaming, raising the possibility that the material world might be an illusion. Finally, he introduced the hypothesis of an evil genius who could deceive us even about mathematical truths.
Why is it Methodical?
Descartes’ doubt was methodical because it proceeded step-by-step. He introduced increasingly powerful criteria for doubt, seeking to find any knowledge that could withstand this scrutiny.
What Criteria are Applied and What Knowledge is Questioned?
- Sensory information: Our senses can be deceiving, so we cannot rely on them completely.
- The distinction between waking and dreaming: How can we be sure that our experiences are not just dreams?
- The evil genius hypothesis: Could an evil genius be deceiving us about even the most basic truths, like mathematics?
What Do I Know and What am I Sure of?
At this point, Descartes has cast doubt on all knowledge. However, he realizes that even if he is being deceived, he must exist to be deceived. This leads to the famous cogito ergo sum: “I think, therefore I am.”
What Good Can This Radical Doubt Be?
Descartes’ radical doubt serves to free us from prejudices and to accustom our minds to distinguish truth from falsehood.
The First Certainty and the Formulation of the Criterion of Truth
From the cogito, Descartes derives his criterion of truth: whatever the mind perceives clearly and distinctly is true. This becomes the model for all subsequent certainty.
- Criterion of truth: What my reason conceives clearly and distinctly is true.
- Model of rational evidence: All truths must be grasped with the same clarity and distinctness as the cogito.
With this first principle and criterion of truth, Descartes aims to rebuild knowledge on a solid foundation.