Understanding the Cogito and the Criterion of Truth
The Cogito and the Criterion of Truth
Doubt, disappointment, and disorientation are the results of years of study. The solution is contained in reason: it is one and the same for all men and their proper use. The method will also be one and the same for all sciences. The philosophical foundation of the method will doubt; it can reach the indubitable truth. There is no doubt that skepticism denies any possibility of knowledge, but it is the methodical starting point for an investigation. This is a voluntary choice to engage in radical doubt to see if it succeeds in uncovering truth.
Reaching Doubt
Doubt encompasses empirical ideas, the existence of an extra-mental world, and mathematical ideas.
The Cogito
The Cogito is not only a statement of existence but also a criterion of certainty. It represents an ontological and epistemological truth.
The Criterion of Certainty
The only two certainties to discard are arithmetic and geometry, as they provide the certainty required for adequate knowledge. Both sciences are examples of a universal science called mathesis universalis.
The Method of Reason
The method of reason is not merely a method; it is based on the structure of reason itself, which has two basic procedures or operations: intuition and deduction.
Intuition
Intuition is the act of reason whereby we immediately grasp a concept or idea so clearly and distinctly that we cannot have the slightest doubt about it. The concepts discarded are called simple natures. When an idea is clear and distinct, we say that it is obvious. This will be the criterion of certainty: the evidence is clarity and distinction.
Deduction
Deduction provides certainty for thoughts that we cannot have a clear and distinct intuition about, as we cannot perceive all the steps of reasoning. Intuition guarantees the certainty of each step, while the overall certainty of all reasoning is given by deduction, which relies on memory.
The Method in the Discourse on Method
The method consists of four rules, with the first two related to intuition and the second two to deduction, ensuring accuracy:
- Rule of Evidence: Do not admit anything as true unless it is evident, carefully avoiding precipitation and prevention. This rule states that the criterion of certainty is evidence, and we must avoid taking as true what is false, as well as refusing to accept what is true.
- Rule of Analysis: Divide each difficulty into as many parts as possible to find the best solution. This allows intuition to establish that a problem should be divided into its simplest parts.
- Rule of Synthesis: Conduct thoughts starting with the simplest objects, gradually rising to knowledge of the most complex. This establishes that we must engage deduction from the simplest, thanks to intuition.
- Rule of Enumeration: Make comprehensive tallies and general reviews to ensure nothing is missed. Since deduction is based on memory, this requires general reviews to assure us of the truth of the conclusion.
This method has always been applied in mathematics and will be equally effective if applied to all objects of human knowledge.