We Fail, We Doubt, We Think, We Feel, We Change… So, Are We?

What makes us real? Is it the mind, the body, or something else entirely? In the 17th century, René Descartes gave us one of the most famous phrases in philosophy: Cogito ergo sum: “I think, therefore I am.” This was the foundation of his concept of Res Cogitans, which translates literally into “a thinking thing” and he meant as the thinking substance, a realm of pure thought separate from the physical world – consciousness. While Res Extensa means "extended thing" and represents the physical world. These two terms represent according to Descartes' philosophy the mind-body dualism. 

Descartes’ radical proposition shaped centuries of thought, reinforcing the idea that consciousness—our ability to think—is what brings us into existence us or makes us real. Was he right? Is thinking alone enough to define us as beings?

Over the years, poets, philosophers, and artists have challenged, expanded, and even subverted cogito ergo sum, questioning what it means to exist. Some, like Antoine Léonard Thomas, expanded and highlighted Descartes to include questioning as the initial source of coming into being. Others, like Audre Lorde, reclaimed it to speak to identity and power. And today, in an age of AI, neuroscience, and digital consciousness, the question is more relevant than ever. It will probably be a relevant question as long as thinking things exist. 

 

Descartes and the Mind-Body Divide

What if everything around you was an illusion? What if your senses were lying? Descartes asked himself these questions in 1641 and came up with a radical answer: I think, therefore I am.

To him, the very act of questioning reality was proof that something must be doing the questioning—a thinking thing (Res Cogitans). That, he argued, was the foundation of our existence. In Meditations on First Philosophy (1641), Descartes sought certainty. He systematically doubted everything—his senses, his body, even the external world—until he found what he believed to be one unshakable truth: he was thinking. Originally published in French in his 1637 Discourse on the Method he states: je pense, donc je suis in. What could arguably be translated as “I am thinking, therefore I am”.  But it is the (in)famous Latin Cogito Ergo Sum (usually translated as I think therefore I am)–his first principle– that will start this exploration. So, he decided, if he was thinking, he must exist. From this, he concluded that the mind (Res Cogitans) and the body (Res Extensa) were separate, with the mind being the true essence of a person. 

Descartes explained in a margin note from Meditations, "We cannot doubt of our existence while we doubt.” Descartes asserted that the very act of doubting one's own existence served—at a minimum—as proof of the reality of one's own mind; there must be a thinking entity—in this case the self—for there to be a thought.

Descartes later wrote to Andreas Clovis, a friend of his mentor Isaac Beeckman, who had shared with him a previous exploration of St Augustine’s on thinking and existence. “He goes on to show that there is a certain likeness of the Trinity in us, in that we exist, we know that we exist, and we love the existence and the knowledge we have. I, on the other hand, use the argument to show that this I which is thinking is an immaterial substance with no bodily element. These are two very different things.” This distinction had profound implications. It placed reason above the body, intellect above emotion, and rationality above intuition. It tore the mind from the body. It also reinforced a dualistic view of human existence that shaped Enlightenment thought, science, and even modern education.

 

The Problem with Thinking Alone: Doubt as the Real Foundation

But is thinking alone enough? If doubting proves existence, then shouldn’t doubt—not just thought—be the foundation of being?

No doubt influenced by this dualistic cue Gottfried Leibniz, belonging to the generation immediately after Descartes, held the position that the mental world was built up by mental objects that are not part of the physical world.  Later the distinction between res cogitans and res extensa was taken up in Baruch Spinoza in Ethics, according to which Thought and Extension are two infinite attributes of the one divine Substance. Soul and body are in turn two finite modes of Thought and Extension.

The earliest known translation as "I am thinking, therefore I am" is from 1872 by Charles Porterfield Krauth, a Lutheran pastor, theologian, and educator, elected member to the American Philosophical Society in 1864. As put by Krauth, "That cannot doubt which does not think, and that cannot think which does not exist. I doubt, I think, I exist.”

Lewes, George Henry (1867). The History of Philosophy from Thales to Comte: Modern Philosophy George Lewis writes in The History of Philosophy from Thales to Compte from 1867 that Decorate has told us: “Doubt as I may, I cannot doubt of my own existence, because my very doubts reveal to me a something which doubts.” So then it isn’t exactly the thinking that triggers our consciousness, but the challenging doubt which does. 

This toying with the idea of what makes us real, what entails our consciousness begins long before Decartes. Early in the fifth century BC, Parmenides for example is quoted as saying "For to be aware and to be are the same". Plato spoke about the "knowledge of knowledge" and Aristotle explains the idea in full length:

“But if life itself is good and pleasant… and if one who sees is conscious that he sees, one who hears that he hears, one who walks that he walks and similarly for all the other human activities there is a faculty that is conscious of their exercise, so that whenever we perceive, we are conscious that we perceive, and whenever we think, we are conscious that we think, and to be conscious that we are. Perceiving or thinking is to be conscious that we exist…"

Again in the early fifth century AD St Augustine, as referenced before says: 

"So far as these truths are concerned, I do not at all fear the arguments of the Academics when they say, What if you are mistaken? For if I am mistaken, I exist." This formulation (si fallor, sum) is sometimes called the Augustinian cogito. And it is incredibly appealing to think that consciousness or awareness can come from being mistaken. It is how we learn, is it not? Through mistakes? Today making and learning from mistakes is encouraged far more than it was at least in my experience growing up. To hold the idea that real consciousness can come from acknowledging errors and thinking through them would help reframe mistakes as valuable and necessary. 

Now we come back to Descartes and his mentor’s friend, Andreas Clovis, who made him aware of St Augustine and his thoughts on consciousness. Descartes wrote back saying: “I am obliged to you for drawing my attention to the passage of St Augustine relevant to my I am thinking, therefore I exist. I went today to the library of this town to read it, and I do indeed find that he does use it to prove the certainty of our existence.”

Also relating to doubt, the 8th century Hindu philosopher Adi Shankara wrote, in a similar fashion, that no one thinks 'I am not', arguing that one's existence cannot be doubted, as there must be someone there to doubt.

The Spanish philosopher Gómez Pereira wrote in 1554 "nosco me aliquid noscere, & quidquid noscit, est, ergo ego sum" ('I know that I know something, anyone who knows is, therefore I am').

The Expanded Cogito

"Ego sum res cogitans, id est dubitans, affirmans, negans, pauca intelligens, multa ignorans, volens, nolens, imaginans etiam et sentiens…" ("I am a thinking [conscious] thing, that is, a being who doubts, affirms, denies, knows a few objects, and is ignorant of many,-- who loves, hates, wills, refuses, who imagines likewise, and perceives"). 

The 18th-century French poet and literary critic Antoine Léonard Thomas wrote an essay in 1765 in praise of Descartes’ idea that thinking defines existence. In the posthumously published The Search for Truth by Natural Light, Descartes had expressed this insight as dubito, ergo sum, vel, quod idem est, cogito, ergo sum ("I doubt, therefore I am — or what is the same — I think, therefore I am”).

Thomas, in particular, argued that questioning is the real starting point—Dubito, ergo cogito, ergo sum (“I doubt, therefore I think, therefore I am”). He writes: ”Puisque je doute, je pense; puisque je pense, j'existe."  Which translates into “Since I doubt, I think; since I think, I exist.” Or in Latin “dubito, ergo cogito, ergo sum.” It is interesting to think that this Expanded Cogito is the one known to have the doubt added, when we know that doubting, and questioning, were part of the discourse even before Descartes. Like with the mistake Cogito, I love the argument that to think or exist first you have to question, to challenge which was not part of the well-known Cogito Ergo Sum. 

 

Then begin the Critiques.

 

Jean Jacques Rousseau : We are real because we feel.

Descartes’ world was one of cold reason. Rousseau thought that was a mistake. If we want to understand what makes us real, we need to look at something more powerful than logic—emotion.

He flipped Descartes’ phrase into something new: I feel, therefore I am. Emphasizing the primacy of emotion and personal experience in understanding existence. For Rousseau, philosophy was not a detached, logical exercise but a deeply personal journey of self-realization and introspection. He believed that true knowledge emerged from engaging with one’s own feelings and experiences, rather than abstract reasoning alone. This perspective marked a shift towards Romanticism, highlighting the importance of individual emotion over Enlightenment rationalism. In his “Reveries,” Rousseau contrasted his approach with that of his contemporaries, stating that while many philosophers studied human nature to discuss it knowledgeably, they did not seek to understand themselves. In contrast, Rousseau’s philosophy was an effort to explore and articulate his own existence, in which he believed thought was not all of existence but a more complete one.

 

Søren Kierkegaard : In order to think, you must already exist.

Kierkegaard called Descarte’s phrase a needless repetition of an idea in his Concluding Unscientific Postscript.  He’s not necessarily referring to the other occasions on which the cogito idea has been explored, more so he argues that the cogito already presupposes the existence of "I", and therefore concluding with existence is logically trivial. Here, the cogito has already assumed the "I"'s existence as that which is thinking. 

What Kierkegaard thinks is the proper logical flow of the argument is that existence is already assumed or presupposed for thinking to occur, not that existence is concluded from that thinking. So, in order to think, you must already exist. 

 

Martin Heidegger : We are real because we die.

But what if we’re asking the wrong question? Maybe what makes us real isn’t thought or feeling—but the fact that we’re going to die. LOL, sorry for that.

Heidegger turned the Cogito on its head. He argued that sum moribundus—“I am, in that I will die”—was the real foundation of existence. For him, death makes us truly individual and gives our existence meaning.

In History of the Concept of Time (1925), Heidegger argues that the real certainty isn’t “I think, therefore I am,” but rather, “I am, in that I will die.” He suggests that instead of defining ourselves by thinking, we should recognize that our very existence (sum) only gains significance through the fact that we are always dying. In other words, being human means living with the awareness that we are always moving toward death, and that realization is what makes our existence authentic.

 

John Macmurray: We are real because we can act.

Macmurray completely rejected Descartes’ Cogito because he believed it placed too much emphasis on thought while ignoring action. He argued that if philosophy is based only on thinking, it becomes detached from reality—just “a bubble floating in an atmosphere of unreality.”

Macmurray saw this focus on thought as creating a deep divide between thinking and action, breaking up the unity of human experience and disconnecting us from the real world. To fix this, he suggested replacing “I think” with “I do,” shifting the foundation of philosophy from thought to action.

 

Alfred North Whitehead: We are always being formed by our thoughts.

In Process and Reality, Alfred North Whitehead flips Descartes’ idea of the thinker creating thoughts. Instead of the thinker producing occasional thoughts, Whitehead’s philosophy of organism suggests that thoughts are what shape and bring the thinker into being. In this view, the thinker isn’t the starting point but rather the outcome of a dynamic process.

This marks a fundamental contrast between two ways of understanding existence: Descartes’ philosophy of substance, which sees the self as a fixed entity that thinks, versus Whitehead’s philosophy of organism, where the self is continuously formed through experiences and interactions.

 

Bernard Williams: We cannot step outside ourselves to prove we exist.

Bernard Williams questioned the idea that thinking can be understood objectively, as if from an outside perspective. He argued that when we say “there is thinking,” it must always be tied to something—it can’t just exist on its own. However, that something can’t be a separate “thinking self” (a “Cartesian ego” which is the idea of a pure "I" or self that is distinct from the body and can exist without it) because we have no way to objectively distinguish one person’s consciousness from another just by examining thoughts.

The core problem is that introspection—our ability to reflect on our own minds—doesn’t give us access to an external, objective truth. No matter how deeply we analyze our own thinking, we can’t use it as proof of a reality beyond our own subjective experience.

 

Antonio Damasio: We are because our emotions and body shape our thoughts.

Antonio Damasio, a neuroscientist, critiqued Descartes’ Cogito, ergo sum in his book Descartes’ Error: Emotion, Reason, and the Human Brain (1994). Like Rousseau, he argued that Descartes’ separation of mind and body (Res Cogitans and Res Extensa) was fundamentally flawed. Instead of thinking of being the foundation of existence, Damasio proposed that feeling —rooted in the body— is what comes first.

His central idea is that emotions and bodily experiences shape rational thought, meaning that the self (the thinking being) is deeply connected to physical processes. He reframes the Cogito as “I feel, therefore I am,” emphasizing that cognition is inseparable from the body and emotions. His neuroscience research suggests that reason and decision-making rely heavily on emotional and bodily states, undermining the idea of pure rational thought as the basis of human existence.

In short, Damasio challenges Descartes by showing that the mind cannot be separated from the body. It is through emotions and sensory experiences that thinking and identity emerge.

 

Audre Lorde: I Feel, Therefore I Am (And That is Revolutionary)

Audre Lorde is another powerful voice reshaping Res Cogitans. Audre Lorde, the poet, essayist, and activist, turned the Cogito into something deeply personal and political:

“I think, therefore I am? No, I feel, therefore I can be free.”

Lorde, a Black feminist and queer writer, recognized that Descartes’ model left out the body, particularly the bodies of those historically ignored or oppressed. For her, feeling was a form of knowledge, a way of resisting systems that demand cold rationality while denying lived experience.

Lorde’s words from Poetry is Not a Luxury (1977) resonate today in movements that challenge structures of power—whether in feminism, racial justice, or queer liberation. Her Res Cogitans is not just a mind thinking in isolation; it is a body, a voice, an identity shaped by experience and emotion. Similarly to Rousseau and Damasio, she emphasizes the power of feeling and expression but reframes it as fundamental to being and to liberation.

 

Res Cogitans in Art, Literature, and Culture

Artists, writers, and thinkers have long played with – dismantled, or restructured— the Cogito. Some have questioned the reliability of thought itself, while others have stretched it to include feeling, embodiment, and even artificial intelligence.

• Surrealists & Absurdists (Dali, Beckett, Borges) say that if thinking proves existence, what happens when thought becomes unreliable? Works like Waiting for Godot and Ficciones toy with fragmented consciousness, questioning whether thought alone can define reality.

• Existentialists (Sartre, Camus, Beauvoir) propose that if existence precedes essence, then Res Cogitans is not a fixed state but a choice. Consciousness is a burden, freedom is terrifying, and meaning is something we must create for ourselves.

• Neuroscience & AI pose a question: Where does Res Cogitans end? If machines can “think,” are they conscious? As AI mimics human reasoning, we must reconsider whether thinking alone is enough to define being.

Today’s artists and writers remix Descartes in new ways—whether through digital identity, post-humanism, or the blending of mind and body in immersive, sensory experiences.

Thinking, Feeling, Becoming

 

So where does that leave us?

Descartes gave us Res Cogitans as a foundation, and over time, thinkers like Thomas, Lorde, and countless others have challenged or expanded it. Today, we might say:

“I think, I feel, I experience, I question, I fail, I challenge, I learn, I change—therefore, I become.”

Existence is not just thinking. It is feeling. It is moving. It is creating. It is becoming. It is not static. It is not immutable.

The understanding of Res Cogitans is not over. It is perpetually evolving. And so are we.

 

 

 

References and Sources

1. René Descartes – Meditations on First Philosophy (1641)

2. René Descartes – Discourse on the Method (1637)

3. Saint Augustine – City of God (426 AD)

4. Jean-Jacques Rousseau – Reveries of a Solitary Walker (1782)

5. Søren Kierkegaard – Concluding Unscientific Postscript to Philosophical Fragments (1846)

6. Martin Heidegger – Being and Time (1927)

7. John Macmurray – The Self as Agent (1957)

8. Alfred North Whitehead – Process and Reality (1929)

9. Bernard Williams – Descartes: The Project of Pure Inquiry (1978)

10. Antonio Damasio – Descartes’ Error: Emotion, Reason, and the Human Brain (1994)

11. Audre Lorde – Poetry Is Not a Luxury (1977)

12. Gottfried Wilhelm Leibniz – Monadology (1714)

13. Baruch Spinoza – Ethics (1677)

14. Charles Porterfield Krauth – Translation of Cogito (1872)

15. George Henry Lewes – The History of Philosophy from Thales to Comte (1867)

16. Adi Shankara – Upadesasahasri (8th Century)

17. Gómez Pereira – Antoniana Margarita (1554)

18. David Chalmers – The Conscious Mind: In Search of a Fundamental Theory (1996)

19. Yuval Noah Harari – Homo Deus: A Brief History of Tomorrow (2016)

20. Nick Bostrom – Superintelligence: Paths, Dangers, Strategies (2014)