Understanding Descartes: Key Concepts and Definitions
Key Concepts in Descartes’ Philosophy
Opinions and Knowledge
Knowledge not recognized as genuine is pre-methodical doubt and the application of the method.
Reason
Reason is man’s natural, innate, general instrument of knowledge: ‘ability to judge well and distinguish truth from falsehood.’ Also called ‘good sense’ and is equal in all men. Therefore, the diversity of opinion comes just as it is applied (method).
Analysis
The second of precepts or rules of method, which is to reduce the complex to its simplest components or elementary.
Evidence
The first precept or rule of method does not accept as true only what comes from an intellectual intuition of clear and distinct ideas. It is, therefore, sensible evidence.
Clear Idea
The one that is present and manifest to an attentive mind.
Distinct Idea
What appears as a separate and cut out of other ideas and cannot be mistaken for any other. It contains in itself anything but clear.
Deduction
Operation of mind by which we infer some things from others: we went from something known to something unknown. It involves some movement or succession. It differs from intuition; intuition is a way of knowing immediately, while deduction is a way of knowing mediately.
Criterion of Certainty
Rule to distinguish the true from the false. Consists in the clearness and distinctness of ideas: ‘It seems to establish (…), as a rule, they are true all the things we conceive very clearly and distinctly’.
Method
A set of simple rules that prevent taking never a mistake for truth. Way forward for the reason to get strong and true judgments. The methodological ideal occupies an important place in the Cartesian system. The scientific method should be ‘mathematical’.
Senses
Passive faculties receiving ideas. They do not inform us about reality itself (the sensible qualities are not formally objective: do not exist as we perceive it), but its function is purely pragmatic: they do not teach the usefulness or harmfulness of things.
Body
Material part of the human being, whose essence is extension. It behaves like a machine governed by the laws of mechanics. The irreducibility of the attributes of the body and soul makes impossible, with Descartes, an adequate explanation of their mutual interaction.
Substance
That which does not need anything else to exist. Descartes distinguished three substances: an infinite (God), and two finite (res cogitans and res extensa).
God
Substance infinite, eternal, immutable, independent, omniscient, in which everything exists. According to Descartes, is ‘causa sui‘. Also, the veracity of God guarantees the value of clear and distinct ideas and ultimately based on the criterion of certainty.
Soul (Me, res cogitans)
Spiritual part of the human being whose essence is thought. Spiritual substance totally separate from the body, even more easily known than he, and even if he were not, in any way would not be all that is.
Essence
It regards my self be true, q q is another thought, the very nature of man is his thought, an essential attribute of his soul, x which is what q is, entirely distinct from the body, and easier to know this.