Portiaudios - La filosofía de Descartes.

Who Was Descartes?

Early Life and Education

• René Descartes, born in 1596, is recognized as the father of modern philosophy and a key figure in rationalism.

• He had a privileged upbringing despite the turmoil of the Thirty Years' War, receiving a Jesuit education at La Flesh, which he later criticized for its scholastic approach.

• After studying law at the University of Poitiers, he joined the army of Maurice of Nassau and traveled across Europe.

Intellectual Development

• In winter 1619, Descartes experienced an intellectual revelation that shaped his future work.

• Fearing persecution from the Inquisition due to his ideas, he moved to Holland where he spent nearly two decades writing most of his philosophical works.

Major Works and Contributions

• His major work "Discourse on Method" laid out his method for directing reason and seeking truth in sciences.

• Influenced by Plato's dualism and Aristotle's logic, Descartes developed a method based on logical deduction.

Key Influences on Descartes

Philosophical Foundations

• He admired ancient mathematics for its clarity and rigor, leading him to create a deductive method.

• Influences included Augustine’s principle "Cogito ergo sum," which became central to his philosophy regarding individual existence.

Scientific Influence

• He adopted Galileo's mechanistic view of nature and experimental resolution concepts while also drawing from contemporaries like mathematicians Viet and Zagmat.

Cartesian Theories

Ontology and Metaphysics

• Developed theories on substances (res), presenting God as a creator who guarantees knowledge.

Anthropological Views

• Introduced anthropological dualism with concepts like the pineal gland's role in mind-body interaction.

Scientific Methodology

Mechanistic Understanding

• Proposed that reality operates like a machine governed by deterministic laws without freedom.

Epistemological Insights

• Emphasized doubt as a methodological tool to establish indubitable knowledge; introduced three types of ideas: innate, adventitious, and factitious.

Goals of Cartesian Philosophy

Foundation for Science

• Aimed to establish solid foundations for scientific knowledge amidst skepticism towards Aristotelian thought.

Metaphysical Underpinnings

• Sought an indubitable core idea capable of withstanding skepticism as part of building modern science.

This structured overview captures key aspects of Descartes' life, influences, contributions to philosophy and science while providing timestamps for easy reference.

Anselm's Ontological Argument and Its Influences

The Nature of God According to Anselm

• Anselm posits that God must exist by definition, as God is perfect and existence is one of His perfections.

• Influenced by scientific revolution figures like Galileo Galilei, particularly in mathematics and mechanics, shaping his concept of res extensa (extended substance).

Influence of Classical Skepticism

• Strongly influenced by classical skepticism from Pyrrho (4th-3rd century BC) and its reformulation by Michel de Montaigne.

• Engaged with Sextus Empiricus (1st-3rd century AD), questioning human reason and the fallibility of senses.

Radical Doubt and Epogé

• Descartes transforms the classical notion of Epogé (suspension of judgment) into radical, universal doubt aimed at finding indubitable knowledge.

• Introduces "Cogito, ergo sum" ("I think, therefore I am") as a foundational truth for knowledge.

Descartes' Ontology: Three Substances

The Three Types of Substance

• Descartes categorizes reality into three substances:

• Res infinita (God)

• Res cogitans (mind/soul)

• Res extensa (body/world).

Understanding Each Substance

• Res infinita: Defined as God with perfection as the main attribute; described through innate ideas based on John Damascene's philosophy.

• Res cogitans: Represents the thinking substance or soul; characterized by thought and reason, producing ideas and exercising freedom.

• Res extensa: Refers to physical substance occupying space; defined by mechanical laws contrasting with the immaterial nature of res cogitans.

Critique from Spinoza

Spinoza's Perspective on Substance

• Critiques Descartes' substantial theory, arguing only one true substance exists—God—while everything else are attributes of creation.

Comparison Between Descartes and Spinoza

• For Descartes, substances exist independently or rely solely on God for existence. In contrast, Spinoza views only God as the true substance.

Cartesian Anthropology: Influences on Descartes’ System

Key Philosophical Influences

1. Plato (5th–4th century BC): Established a dualism between soul and body; emphasized the independence of the soul.

2. Skepticism: Figures like Pyrrho challenge universal knowledge; Descartes develops methods to counter this skepticism through individual certainty.

3. Aristotelian Scholastic Tradition: Distinction between matter (body) and form (soul); informs Cartesian dualism between res cogitans and res extensa.

4. Augustine of Hippo (3rd–4th century): Shares themes with Descartes regarding introspection leading to undeniable mental existence.

The Cartesian Dualism and Its Foundations

Historical Context and Influences

• The concept of "res cogitans" (thinking substance) is introduced, linking to Thomas Aquinas and Scholasticism in the 11th century, which revived the study of substance theory.

• Key figures of the Scientific Revolution, such as Copernicus, Galileo Galilei, and Kepler, proposed mechanistic explanations for the natural world based on movement and extension.

Descartes' Methodology

• Descartes adopts clarity and distinction as foundational principles of his Cartesian method, emphasizing judgment as a process leading to results.

• He establishes a dualism influenced by Platonic, Aristotelian, and Scholastic traditions that differentiates between body (res extensa) and soul (res cogitans).

Substance Theory

• Descartes defines "res cogitans" as an immaterial thinking substance characterized by thought or reason; it contrasts with "res extensa," which occupies space and has material attributes.

• The pineal gland is identified by Descartes as a bridge between mind (spiritual/inimmaterial) and body (material), serving as a control center for sensory perceptions.

Interaction Between Mind and Body

• The pineal gland's uniqueness lies in its singularity within the brain; it coordinates sensory perceptions through 'animal spirits,' small particles moving through nerves.

• Descartes uses terms like anima (soul), mens (mind), interchangeably referring to res cogitans. This mind is defined as immaterial and not locatable within physical space.

Mechanistic View of the Body

• In Cartesian philosophy, the body is part of res extensa with geometric properties; qualities like color or taste are subjective effects perceived by the mind rather than inherent characteristics.

• For Descartes, matter lacks life or internal force; he rejects teleological causes in favor of efficient causes that explain motion or production without invoking purpose.

Critique of Cartesian Dualism

• The theory of homunculus critiques arise from Descartes’ ideas about perception—if a mini self perceives images in the brain, who observes those images?

• This leads to an infinite regress problem where each observer requires another observer ad infinitum to explain perception effectively.

Conclusion on Perception Issues

• Philosopher Daniel Dennett critiques this aspect of Cartesian interactionism by highlighting how introducing an internal observer does not resolve but complicates understanding perception.

• Ultimately, this critique illustrates that merely positing an internal viewer creates endless cycles without reaching fundamental explanations regarding mind-body relations.

Scientific and Physical Theory of Descartes

Influences on Descartes' Theories

• Descartes was significantly influenced by the mechanistic view of his time, scholastic substance concepts, Anselm of Canterbury's theology, and John Damascene's concept of God.

• He utilized Galileo Galilei's clockmaker metaphor to describe an infinite network devoid of freedom.

Key Areas of Study in Physics

• Descartes' contributions to physics are categorized into six areas:

• Mechanism

• Laws of Nature

• Cosmology (theories about the universe)

• Physiology

• Optics

• Scientific Method

Mechanism and Natural Laws

• The mechanistic view posited that space is a plenum, completely filled with matter, opposing views from authors like Gassendi.

• The principle of inertia states that an object at rest remains at rest and an object in motion continues in motion unless acted upon by external forces.

Cosmological Theories: Vortex Theory

• Vortex theory is discussed in works such as "Lemont" and "Principia Philosophiae," both published in 1644.

• This theory describes the universe as a plenum filled with a subtle fluid called ether, which governs movement through fixed quantities imparted by God.

Composition and Movement in the Universe

• Cosmic vortices result from particle collisions within a non-vacuum universe, generating circular movements that create matter.

• In this model, lighter particles form suns at vortex centers while heavier particles form planets around them.

Gravitational Concepts and Material Types

• Instead of gravity as an attractive force, Descartes explained planetary motion through ether flow vortices. Gravity was viewed as pressure from finer particles.

• He identified three types of materials: luminous, transparent, and opaque.

Physiological Explanations

• Descartes reduced biological functions to physical-mechanical explanations using mechanical analogies for body parts (e.g., heart as a heat pump).

• He claimed animals lacked souls and were mere physical mechanisms without mental capacity.

Contributions to Optics

• His notable work "Dioptrique" (1637), accompanying "Discourse on Method," outlines key optical principles:

• A. Light is rapid movement transmitted through air or ether.

• B. Light consists of small particles (corpuscles).

Refraction and Reflection Theories

• Developed theories on light refraction based on mechanical principles known today as Snell's Law.

• Established relationships between angles of incidence and reflection; compared human eyes to camera obscura for lens manufacturing guidance.

Scientific Methodology

• Emphasized reason as the primary tool for truth-seeking; proposed a deductive method starting from first causes—God as creator and natural laws.

Mathematical Contributions

• In "La Géométrie" (1637), he laid foundational mathematical ideas influenced by earlier mathematicians like Euclid for deductive rigor.

Influences on Cartesian Mathematics

• Notable influences include Apollonius’ coordinate systems leading to Cartesian coordinates; Archimedes’ methods for area calculations; contributions from Italian algebraists resolving cubic equations crucial for Cartesian mathematics.

Contributions of Descartes to Mathematics

Key Contributions

• Descartes made four main contributions to mathematics:

• Development of analytical geometry using Cartesian coordinates.

• Introduction of mathematical notation, utilizing letters for unknowns (X, Y, Z) and known quantities (A, B, C).

• Creation of methods for solving algebraic equations.

• Distinction between algebraic curves and mechanical curves.

Epistemology and Methodology

• In "Discourse on the Method" (1637), Descartes aimed to establish a scientific foundation based on reason, particularly in optics, meteorology, and geometry.

• His motivation stemmed from the decline of Aristotelian scholastic knowledge and the need for solid scientific principles grounded in rational thought.

Rationalism vs. Empiricism

• Descartes is recognized as the founder of rationalism, opposing empiricism by emphasizing reason over faith or authority.

• He proposed a method that ensured consistent progress through reasoning while rejecting sensory knowledge as inferior.

The Role of Ockham's Razor

• Influenced by William of Ockham’s principle that simpler explanations are preferable; this led Descartes to simplify ideas during analysis.

Steps in Cartesian Method

• In "Regulae direction in ingeni," he defined his method as rules ensuring truth discernment without confusion or fatigue.

The Concept of Epoche in Cartesian Philosophy

Redefining Epoche

• Unlike classical interpretations which viewed epoche as suspension of judgment leading to uncertainty, Descartes used it systematically to filter doubt from beliefs.

Characteristics of Cartesian Epoche

• Radical doubt: questioning all assumptions thoroughly.

• Universal application: applying doubt across all reality without exception.

• Theoretical results: focusing on ideas that can be mathematically expressed.

• Methodical approach: establishing a structured process for inquiry.

Four Steps of the Cartesian Method

• Evidence: Initial clarity required before proceeding with any idea.

• Analysis: Breaking down complex concepts into simpler parts.

• Synthesis: Reconstructing understanding from analyzed components.

• Enumeration/Verification: Checking results against established truths.

Intuition and Rational Knowledge

Immediate Knowledge Through Reason

• Rationale behind intuition emphasizes immediate access to truth via clear understanding devoid of doubt.

Methodology of Knowledge: Descartes' Steps

Analysis and Synthesis in Descartes' Method

• The second step is analysis, which involves breaking down complex ideas into simpler ones for clearer understanding. This method draws inspiration from the Padua school.

• The third step is synthesis, where partial intuitions are combined to form a coherent knowledge free from errors. Synthesizing means reassembling insights.

• The fourth step is enumeration or verification, reviewing the entire process to ensure no errors exist and that knowledge is accessed intuitively.

Descartes' Epistemological Findings

• Descartes begins by discarding unreliable sensory information as a source of knowledge, opposing empiricism. He uses examples like circular towers appearing square upon closer inspection.

• He also dismisses bodily sensations derived from senses due to their fallibility, citing phantom limbs experienced by soldiers during war.

• Information about the external world is questioned as well; he doubts the reality of people walking on streets, suggesting it could be an illusion.

Doubts and Radical Skepticism

• Descartes questions the distinction between dreams and wakefulness, referencing Calderón's "Life is a Dream," highlighting our inability to differentiate memories from dreams.

• He proposes simplifying complex reasoning through analysis to avoid errors. After discarding sensory information, he introduces the concept of an evil genius manipulating perceptions.

The Role of God in Certainty

• To counteract the possibility of an evil genius deceiving him, Descartes introduces God into his framework as a non-deceptive being who guarantees truth due to His goodness and omnipotence.

Cogito Ergo Sum: The Foundation of Knowledge

• Through this method, Descartes arrives at his famous conclusion: "Cogito ergo sum" (I think therefore I am), asserting that doubt itself confirms existence as a thinking being.

Types of Ideas According to Descartes

• He categorizes ideas into three types:

• Innate Ideas: Present since birth; universal concepts requiring no demonstration (e.g., mathematical entities).

• Adventitious Ideas: Derived from senses; discarded for scientific knowledge due to their unreliability.

• Factitious Ideas: Constructed by combining other ideas; dependent on human will.

Provisional Morality Framework

• In seeking ethical truths while acknowledging action urgency, Descartes formulates provisional morality based on four maxims:

• Obey laws and customs of one's country.

• Act decisively with firmness.

• Change personal opinions before altering societal order.

• Review all possible occupations to choose wisely.

Understanding Freedom in Cartesian Philosophy

The Nature of Freedom

• Descartes defines freedom as one of the most fundamental and common notions inherent in human nature.

• The foundation of Cartesian morality lies in the commitment to rationality, suggesting that freedom involves submitting one's will and desires to reason.

• According to Descartes, freedom is considered the fundamental perfection of man, a clear and distinct idea as evident as "Cogito, ergo sum."

• There is a connection between anthropological dualism and provisional morality; the mind (res cogitans) is free and capable of decision-making.

• In contrast, the body (res extensa), being physical, is subject to mechanical laws and determined by them; thus, reason must govern bodily impulses.