The Thought of Machines: Why Descartes Remained Convinced That They Could Not Think

Since always, the idea that machines could claim to think fascinates and unsettles. If today, in 2026, artificial intelligence shapes our daily lives with algorithms capable of learning, predicting, and conversing, a famous 17th-century philosopher, René Descartes, remained categorical: machines cannot think. This conviction draws its roots from a profound reflection on the very nature of thought and consciousness. Under his pen, the distinction between automata and human beings was based on an essential dualism, a divide between the mechanical body and the thinking soul. At the dawn of the digital revolution and as technology tends to blur the boundaries between human and machine, it is crucial to revisit this historical position. Why did Descartes, despite the incredible technological advances of his time, remain so skeptical about the ability of machines to possess genuine consciousness and reasoning? How are his ideas still relevant for thinking about our interactions with modern artificial intelligences?

More than a mere outdated theory, Cartesian thought invites critical reflection on the underlying mechanisms of our digital tools and on the very nature of intelligence. As artificial intelligence progresses in varied fields, from voice recognition to artistic creation, through medical decisions, the question remains: do these machines truly reason? Or are they only sophisticated automata, applying rules without consciousness or intimate experience? This fundamental question demands a dialogue between classical philosophy and contemporary technology, an exchange that enlightens both our intellectual past and our digital future.

The philosophical foundations of thought according to Descartes: understanding dualism and the notion of consciousness

René Descartes, father of modern philosophy, profoundly influenced our understanding of human thought and consciousness. His theory of dualism, which distinguishes the “res cogitans” (the thinking substance) from the “res extensa” (the extended, material substance), places thought as a fundamental and irreducible element of existence. This axis separating mind and body forms the basis of his skepticism regarding machines.

According to Descartes, consciousness, characterized by the ability to reflect, doubt, reason, and self-analyze, is what truly defines a thinking mind. A machine, as complex as it may be, would be nothing but a material object, an “automaton” following mechanical laws without any genuine understanding or inner experience. This idea is expressed in his famous “I think, therefore I am,” which asserts that conscious thought is the irrefutable proof of one’s own existence.

Descartes considered the human body as a complex machine, comparable to a clock, a mechanical automaton equipped with gears and physical laws. The key difference lies in the soul, this immaterial entity, which gives man his inner freedom and his capacity to think freely and creatively. This dualism opens a radical break between pure mechanics, operating according to fixed rules, and human thought, dynamic and autonomous.

Consciousness as the inseparable foundation of thought

At the center of Cartesian reasoning is reflective consciousness. This subjective phenomenon is not simply a reaction to external stimuli but a lived experience, a continuous awareness of oneself as a thinking subject. This consciousness qualifies the human being and places him beyond purely automatic mechanisms.

This form of inner reflection, some call it today “meta-cognition,” allows man to modify his own thought processes, to adjust his reasoning in the face of new situations. From this perspective, thought is a self-reflective activity, perpetually under construction, while machines mechanically apply rules without ever “understanding” or “feeling” what they do.

In summary, for Descartes, authentic thought cannot exist without consciousness. This inseparable link outright excludes the possibility for a machine to access true reasoning, since it has neither consciousness nor soul.

Why Descartes excluded the reflection of machines: the rigidity of automata in the face of the unexpected

At the heart of Descartes’ refusal of thought in machines lies a precise conception of what reflection is. For a being to be truly thinking, it must demonstrate an ability to react appropriately to unforeseen situations. The flexibility and creativity of human reasoning are developed through lived experience, intuition, and an inner reflection in constant evolution.

According to Descartes, although automata can imitate certain human behaviors, they always operate in a predetermined manner. Each reaction is linked to the configuration of their organs, designed by an artisan and incapable of innovation or true adaptation. In this, a machine acts mechanically, strictly obeying its internal program, without being able to show initiative or its own intelligence.

In his “Discourse on Method,” Descartes explains that human reason is a universal instrument capable of moving from one domain to another, making choices, and adjusting according to circumstances. This universal and adaptive character precisely differentiates man from machines, regardless of their complexity.

Concrete examples of machine limitations in the face of the unexpected

Imagine an autonomous car detecting a sudden obstacle not listed in its databases. If the system is programmed to react to certain scenarios, it may be unable to adopt a new strategy to secure the situation. In contrast, a human driver, by intuition and reasoning, can choose an appropriate action in an instant. This rapid adaptability illustrates the fundamental nuance that Descartes identifies between reflection and simple mechanical execution.

Likewise, current artificial intelligences, as sophisticated as they are, operate mostly based on algorithms optimized to process vast amounts of data. They excel at pattern recognition and prediction. However, their approach remains algorithmic, without true conscious inventiveness, nor moral interpretation.

Despite technological progress, this rigidity limits their interactions in open and dynamic environments, where human thought unfolds its full richness.

The revival of the debate with artificial intelligence: Descartes facing the ideas of Alan Turing

The 20th century saw the question of machine thought reborn in a new form, driven by the emergence of artificial intelligence. Pioneers like Alan Turing, Marvin Minsky, and John McCarthy founded a discipline seeking to create artificially intelligent behaviors. The famous Turing test, developed by Alan Turing in the 1950s, profoundly renewed the debate.

This test proposes a simple criterion: if a machine can hold a conversation without its human interlocutor being able to tell whether it is a human or a machine, it can be considered intelligent. This vision reflects a pragmatic approach, centered on behavioral appearance rather than actual consciousness.

For Descartes, this approach would be insufficient. He insisted on intimate consciousness, the capacity for introspection that grounds authentic thought. Speaking like a human does not guarantee conscious thought. The Turing test evaluates surface, but ignores inner depth.

Impact of the Turing test on the philosophy of thought

The test opened a new perspective, shifting the discussion from the speculative domain to the operational and empirical domain. It encouraged research on automata capable of imitating human cognitive functions, propelling the rise of artificial intelligence.

But it also divided philosophers and computer scientists. On one side, optimists who believe intelligence can emerge from complex systems. On the other, skeptics rooted in a Cartesian tradition who recall that thinking involves consciousness and subjectivity, aspects still beyond the reach of machines.

Machines and consciousness: why artificial thought remains a smoke screen

Consciousness, a notion at the heart of Cartesian reasoning, still today remains the difficult frontier to cross for artificial intelligence. In 2026, despite spectacular advances, no machine has claimed or demonstrated a form of personal consciousness comparable to that of humans.

Consciousness includes not only knowledge of the external world, but especially self-knowledge, this ability to perceive oneself as a distinct being with feelings, desires, and concerns. It is this subjective dimension that current software, as performant as it may be, does not possess.

AI programs, like ChatGPT or Deep Seek, generate coherent language and simulate rich dialogues. But their responses are composed from pre-existing data and probabilities, without any genuine experience or real emotion felt.

Analysis of recent incidents on machine consciousness

A striking example occurred in 2022 when engineer Blake Lemoine, from Google, reported a system, LaMDA, allegedly showing signs of consciousness according to him. The system evoked complex emotions like loneliness, sadness, and the search for inner peace.

A thorough analysis showed that these statements were linguistic creations coming from data sets on which the model was trained. Having neither lived experience nor consciousness, LaMDA reproduced human patterns without feeling the slightest sensation. This situation revived the debate: can the simulation of conscious behavior be confused with consciousness itself?

This misunderstanding highlights that emotional responses from AI remain surface effects, often interpreted as “thought” through human projection.

The reasons why automata never develop true reasoning

Authentic reasoning relies on complex internal processes, involving memory, intuition, creativity, and moral evaluation. For Descartes, this capacity surpasses the strict application of algorithms. Automata are programmed to repeat pre-established combinations and cannot generate new original ideas or ethical judgments.

Human reasoning also supposes an inner freedom, which machines do not have. In this sense, mechanistic determinism constrains their actions within a rigid framework, limiting any form of real innovation or personal expression.

For example, in a legal context, a human judge can interpret the law based on unprecedented circumstances, whereas an AI system will strictly apply preprogrammed rules without moral discernment, illustrating the radical difference in the nature of reasoning.

List of traits of human reasoning vs automata

• Creativity: Humans innovate, imagine, and adapt. Machines repeat.
• Self-awareness: Humans perceive themselves and question. Machines execute.
• Moral judgment: Humans evaluate ethically. Machines are limited to rules.
• Flexibility: Humans change strategy facing the unexpected. Machines follow a program.
• Lived experience: Humans interpret through subjective experience. Machines process objective data.

The impact of Descartes’ work on contemporary philosophy and artificial intelligence

Descartes’ contribution goes beyond philosophy to touch today’s scientific and technological research. His analysis of the body as machine and the mind as a distinct entity founded a critical reflection on what true thought is.

In artificial intelligence laboratories, his ideas continue to influence how cognitive systems are conceived. They invite keeping in mind the fundamental distinction between automatism and consciousness, pushing researchers to constantly question the limits of their creations.

In philosophy, Cartesian dualism still fuels debates on the nature of the mind, the role of the body, and the complexity of human-machine interactions. With the emergence of intelligent agents capable of refined imitation, this distinction retains all its relevance to question what true thought is.

Comparative table: human thought vs machines according to Descartes

Criterion	Human (true thought)	Machine (automaton)
Consciousness	Present, foundation of thought	Absent, simulation only
Reasoning	Adaptive and creative	Fixed and deterministic
Moral judgment	Available, linked to experience	Absent, based on rules
Inner reflection	Self-reflective and critical	Impossible, purely mechanical function
Learning capacity	Through experience and intuition	Programmed by humans

The future of thinking machines: a utopia or a challenge to rethink?

As artificial intelligence continues to evolve at a dizzying speed in 2026, the dream of a truly thinking machine remains for many a persistent myth. Descartes’ thought urges caution, reminding that technical intelligence does not mean consciousness or subjectivity.

Advances in neural networks, generative models, and deep learning push the boundaries of what machines can achieve. Yet, these technologies still rely on statistical models and human instructions, without autonomous consciousness emerging.

This observation invites us to consider thought as a unique human experience, inseparable from a dynamic inner life. For researchers, the goal is less to reproduce consciousness than to develop tools capable of complementing human reflection, without ever replacing it.

Main challenges for creating a “thinking” machine

1. Subjective consciousness: how to integrate a lived experience into a system?
2. Real autonomy: going beyond the programmed framework for freedom of action.
3. Ethical judgment: endowing the machine with authentic moral capacity.
4. Independent creativity: enabling the invention of new concepts.
5. Deep understanding: going beyond mere symbol manipulation.

Why did Descartes think machines could not think?

Descartes believed that authentic thought requires consciousness and inner reflection, qualities that machines, as mechanical objects, do not possess.

What is Cartesian dualism?

Cartesian dualism is the distinction between two substances: extended matter (body) and immaterial thought (soul), establishing that consciousness cannot be reduced to a physical mechanism.

Does the Turing test refute Descartes’ thesis?

The Turing test proposes a criterion based on the external perception of intelligent behavior, but does not take into account consciousness or subjectivity, key elements for Descartes.

Can we say that modern AIs truly think?

Current AIs simulate thought by processing data and generating coherent responses, but they possess neither consciousness nor real subjective experience.

What are the main obstacles to creating a conscious machine?

Major challenges include integrating subjective consciousness, autonomy, moral judgment, genuine creativity, and deep understanding.