The Death of the Subject in Art – Part III: Descartes, Spinoza, Leibniz and the Architecture of Reason
The Rational Subject and a Hint of His Art
It is not my intention to sail across the entire sea of the history of ideas. Therefore, after having briefly surveyed the etymology of the concept of the “subject,” I wish to begin a more coherent inquiry into the foundations of the subject’s structure as it became known in modern thought. I will start from the ideas that led the spirit of reality toward modernism, and man toward his maturity — the Age of Enlightenment.
The seventeenth century — aside from wars such as the Thirty Years’ War, the endless conflict between Catholics and Protestants, extreme despotism, and the battles of the Ottoman Empire with the Holy League (Kamen, 1978) — is remembered mainly for the solid groundwork it laid beneath the heavy feet of the enlightened world. The policies of several European monarchies encouraged the flourishing of cultural and artistic disciplines. During the reign of Louis XIV, for example, figures such as Molière, Jean Racine, and René Descartes emerged. Wilhelm I of Prussia promoted immigration, free trade, and religious tolerance. Metropolitan cities were born, bringing with them the urban aura of economy, intellect, creation, spirit, and academia (Burke, 1994).
In the great cities — as once in Athens — a rational inquiry reawakened, one that had ceased for nine hundred years during the Middle Ages (when the world was too preoccupied with barbaric invasions, inquisitions, pagan crusades, civil wars, and struggles for crowns). This renewed investigation of the primordial source — the “substance,” the “given,” the “origin,” as discussed in the previous chapter — was now approached from a more rational and empirical, and less theological, angle. These investigations generated political, philosophical, and scientific revolutions (Newton, Galileo, Bacon, Kepler, Hobbes, Locke, and others). The new thought asked: how can the structure of the object, society, and man (the given data of existence) provide an explanation of the world? What is the nature of knowledge (ethics, society, law)? How is the truth of existing knowledge conceived? What are its limits — induction, deduction, intuition? (Burke, 1994)
Here the colosseum was built for paradigms concerning the subject’s perception of his objects: in rational inquiry, nothing exists that cannot be mapped by the human intellect — whether divine and transcendent or material and finite. Thus society itself and its idols underwent a process of rationalization; science and Protestant faith dispelled the magical, dogmatic enchantments that had ruled the world.
“Each new fact may necessitate the re-adjustment of the relations between end and indispensable means, between desired goals and unavoidable subsidiary consequences […] A subjectively ‘rational’ action is not identical with a rationally ‘correct’ action… one which uses the objectively correct means in accord with scientific knowledge. Rather, it means only that the subjective intention of the individual is planfully directed to the means which are regarded as correct for a given end. Thus a progressive subjective rationalization of conduct is not necessarily the same as progress in the direction of rationally or technically ‘correct’ behavior… An increase in the subjective rationality and in the objective-technical ‘correctness’ of an individual's conduct can, beyond a certain limit — or even quite generally from a certain standpoint — threaten goods of the greatest (ethical or religious) importance in his value system.” — Max Weber
Rational inquiry demanded direct, subjective involvement. The irrational notion of historical events often attributed to “fate” or “chance” became impossible. Purpose was aligned with thought. Rationalism defined the content of our concepts according to internal, a priori sources (perfection of nature, rational knowledge, innate ideas), beyond the sensory data supplied by experience and observation — in a return to Plato. The innate, divine concepts — those necessarily true and good — formed a non-egocentric foundation for human understanding. The empirical, sensory world, on the other hand, brought those concepts into consciousness, often in distorted form. Thus, ontology itself was granted legitimacy by philosophy’s reflection on the structure of the subject. This structure, during this period, was determined by the question of body and soul — of substance and world.
The rationalist system, in its attempt to redefine the Subjectum or Hypokeimenon, asked again: what is the most rational foundation, the one that cannot deceive? The foundation from which one may begin to think reality logically, truthfully? How can human reason decipher substance as a closed, systematic, and lawful totality? From there arises another question: where does the individual stand within that substance — before it, inside it, or beyond it? The constitution of reality is also the interpretation of abstract existence through the tools of the intellect.
Thus, in his rationalism, Descartes sought to isolate the subject through dualism: the division between body and soul, mutable object and pure subject. When Descartes examined his own reality, he found that his senses and his speculative knowledge deceived him, that existential proofs were insufficient, and that even geometry could “lie.” From this he arrived at his famous cogito: “I think, therefore I am,” as formulated in Meditations on First Philosophy. The cogito is expressed even more clearly in Discourse on the Method:
“I noticed that while I was trying to think that everything was false, it was necessary that I, who was thinking this, should be something.”
This statement, the most certain and solid of all, became the first principle — the foundation — of Cartesian philosophy.
o distinguish the soul, Descartes argued, we must “form a clear and distinct idea of it.” We can divide the objects of the world until we reach the human soul, which alone is certain, for it can be conceived only as indivisible. The declaration of the cogito is not a one-time statement, but a process — a meditation — that must constantly renew itself. At every moment, man must reassert himself (“I am the one who thinks, therefore I necessarily exist”) against the deceptive nature before him. The essence and nature of every selfhood is thought; this thought entails no body or space. Hence, the ability to doubt every truth external to the body becomes the very force of existence — subjectivity. The body, by contrast, is but a statue (or machine) shaped by the earth.
In broad terms, we may say that the subject’s action is “true” only when it arises from his inner spiritual perfection. Yet this is not entirely correct, for body and soul are united: the errors of the body (the senses) in distinguishing the true from the false lead to errors that appear in the judgments of subjective reason. To avoid the distortions that intellect proposes, the “I” that thinks must abstain from all external influence. The more one inclines toward subjective perfection, the less one errs — for goodness and truth dwell with certainty within it. Therein also lies freedom.
Descartes advised the thinker to reject all prior knowledge and distrust any external truth that has not passed through the mediation of the inner — of God:
“Custom and example persuade us more than any certain knowledge.”
To prove the existence of bodies as real for the thinking subject — “perfections not contained in me at all” — Descartes reasoned that there must exist another being, more perfect than himself, on whom he depends and from whom he has received everything he possesses. This eternal and complete being is God, and the human “I” is the spiritual link to this divine substance. Opposite God, the “I” always retains lack (negation) — the absence of completeness that defines finitude — “And I find that I am a kind of middle between God and nothingness.” The deficiencies of existence (falsehood, sadness, instability, doubt) are not found in the primordial, divine substance of completeness, but are born from the dependence of the self on external notions.
Every subject, even one lacking Descartes’ intellectual towers, can find here the basis for self-meditation — a wonder at inner truth. To truly understand and feel reality, to gain certainty, the subject must engage his reason and think in the first person. Sense alone — which pertains to material things — cannot provide security. There is no direct connection between what we sense or imagine and what is truly real and good. Only thought — a non-extended soul, in contrast to the extended body of sensations, memories, and images — when in symbiosis with the body, sustains the existence of the object. This is the immanent motion generated by the soul, as opposed to the external motion produced by the body.
“All things that we perceive very clearly and distinctly are true, only because God exists or is, and that He is a perfect being, and that everything that is in us comes from Him.”
When the senses activate imagination, they orient us toward the object before us; thus, the object itself is not a complete being, but an object of consciousness. No objectivity can have ontological status apart from the subjectivity that grasps it. The subject must perform a kind of objectivization of the world — and of his own body — in order to perceive its mechanism and functioning, and thereby recognize that their activity derives from understanding alone.
From this, I learned that the idea of God precedes the idea of self — only through comparison with the infinite do I recognize my own limitations. Man’s yearning and questioning are impossible without the idea of infinity within him: the knowledge of a perfection greater than himself.
Thus, the intellect, when it perceives from a distance an object, does not imagine its ontological magnitude, for reason does not accept it as true:
“The mind does not conclude at all that what we see or imagine in such a way is true; it only concludes that all our ideas or notions must have some basis of truth.”
Man is a thinking being; and as this being comprehends its subjective capabilities, reality itself transforms — it becomes a world “of his own,” newly constructed, a world he can judge as “certain.” The very capacity to raise doubt regarding the finite and infinite world leads to the supreme truth — existence itself. Only through this subjectivity does objective reality derive its validity, not the other way around.
In the same rationalist spirit, Spinoza sustains his monism. For Descartes, the body is an extended substance and the soul a divine consciousness. For Spinoza, the body is a mode of God under the attribute of extension, and the soul is the idea of that body — an idea of an idea — under the attribute of thought. The “I” is a mode of nature; that is man himself. Just as the soul is not separate from the body, so too the world is not separate from God.
“The mind and the body are one and the same thing, which is conceived now under the attribute of thought, now under the attribute of extension. Hence it follows that the order and connection of ideas is the same as the order and connection of things.” (Ethics, II, prop. 7)
Man is not a separate substance, nor is he a “kingdom within a kingdom,” as many of Spinoza’s contemporaries held. There exists only one infinite substance containing all attributes — Deus sive Natura (“God or Nature”). This nature operates by perfect order and law; every phenomenon, every advance and regression, every historical moment, every thought — all unfold according to the necessity of the One. “If two things were not identical, they could not exist together in one subject, for that would entail contradiction.”
Reality unfolds within total determinism. Even when the soul desires, it acts as a consequence of the total chain of causes — it is but one side of thought. What defines and distinguishes the human being is his existence as an attribute of the kingdom of being — an infinite intellect. Within this kingdom, the object is not a separate mechanism but a unit within a perfect order; it is a quality that thought can recognize without difficulty. Unlike Descartes, who erected a wall between self and reality, Spinoza sees consciousness and thought as beginning in the primary substance that includes all multiplicity. Every unit can be understood naturally as an attribute of the idea of body (mind). The mind perceives the actual existence of objects through the idea of the One — the recognition of eternal, infinite essence.
“We endeavor to form the idea of man under the aspect of a model of human nature.”
Though man acts from desire (the commands of the soul), both body and mind, as expressions of nature’s necessity, participate in the same law. Despite being distinct attributes of one substance, they share a parallel connection between the order of ideas and the order of things. The physical and the psychological thus correspond within a single reality — a nearly absolute solution to Descartes’ psychophysical problem.
“An individual composed of many parts retains its nature, whether at rest or in motion, so long as each part preserves its motion and transmits it to the others as before.”
The events of the body mirror those of the mind; the causal chain of physical expansion parallels the immanent causality of the soul’s events. Man is a link in the chain of divine modes, not their origin. This may suggest fatalism, yet on the contrary: when man understands his unique place as part of nature’s order, he becomes an active subject — moving freely toward the good and the primordial whole. The subject may define goodness by acting according to his natural essence. Every free being acts from the necessity of his own nature — from itself. This is again God, or Nature.
To this freedom — to the “in-itself” — man aspires. Acting from within himself, as a mode of nature, he becomes free of external necessity; he acts not for an end but for the value of the act itself.
“Thus, desire is the very essence of man, by which he is necessarily determined to those things which serve for his preservation; and hence man is determined to do them.”
From Spinoza’s psychological analysis I learned that man cannot be free, for there are concrete causes for all his actions — causes of which he is not always aware. To understand human behavior, one must analyze actions “as though they were questions of lines, surfaces, and bodies.” Human purposes are born with his desires. When a man builds a house to live in it, he acts according to his desire, imagining the advantages of domestic life — the image itself becomes the desire.
Like Descartes’ “I” (soul), Spinoza’s “I” (body and soul) is limited by stronger natural attributes — finite and infinite. The subject can change only within the field of its own understanding — its nature — the domain of its adequate cause: a cause that includes a distinct and clear understanding of its origin. The strength of man lies in his capacity for free, reasoned action, guided by the understanding of causes. The free man acts from knowledge; the enslaved man acts blindly, driven by passions whose causes he cannot discern. “He will do things of which he is ignorant.”
the 1670s, in his modest house in The Hague, Spinoza received a visitor — the philosopher Gottfried Wilhelm Leibniz. Leibniz admired Spinoza’s radical thought and was among the few who understood his early works, which were written in a dense, geometric, and logical style of causes and consequences (Strathern, 2000). Some claimed he admired them so much that he began to copy them. Yet, this was precisely the spirit of the age that spoke through these philosophers.
Like Spinoza, Leibniz rejected much of the philosophy of his time (many of whose writers were themselves students of Descartes). He was wary of conceptions that treated man as a “machine” and criticized those who blurred the line between the natural and the artificial. Leibniz sought the exact point where the body interacts with the soul, and how one created being could enter into relation with another. For him, both body and soul exist prior to their birth — like physical ideas — and what we call “generation” is merely “development,” while death is “contraction,” much like in Aristotle.
Continuing Spinoza’s dialogue, and opposing Newton, Leibniz argued that each separate body is also a reflection of the entire world — that every part expresses the whole, only from a different point of view:
“Each substance is like a complete world, a mirror of God or of the entire universe, expressed according to its own manner… it is surrounded by a mass composed of an infinite number of other monads […] through whose actions it represents, as it were, the things outside itself. This body is organic and constitutes a machine of nature.”
The subject of the world is both the complete being and the individual entity — what Leibniz called a Monad. The content of each subject is what defines it: the particular order in which its properties are arranged, its unique sequence among infinite relations and attributes — this is its essence. The Monad serves as the center of each body and the principle of its individuality. The world itself is a pre-established harmony, its rhythm performed in constant parallelism between body and soul.
“The concept of the subject always contains that of the predicate, in such a way that one who understands perfectly the notion of the subject would thereby also judge that the predicate belongs to it.”
The properties of objects exist only insofar as they embody the subject’s complete perception — one that includes its entire existence, past, present, and future. The subject is viewed from a metaphysical unity of its content and essence; multiplicity itself arises from space and time, which are not absolute but relational. The relation between points in space and time establishes the subject’s relation to its object — to another subject.
Rationalism had already taught that whatever is immaterial — mind, spirit, emotion, thought, idea — cannot be decomposed. Here, Leibniz adds: it is also what composes everything that can be decomposed — matter. If the world, like man, is made of innumerable entities, atoms, and substances that all share a spiritual origin, then reality and humanity are both forms of mind. Every object’s conceptual core is a Monad — the “simple substance” underlying all compounds, simple in that it has no parts. The mind, as an individual entity, includes all that can be attributed to it. It is not merely a perceiving consciousness but one that can sense itself as both distinct and plural — as the world itself. Out of this plurality, it selects its own unique structure.
Thus, the given world (its essences and attributes) is not necessary but the best possible. Man, like the world, stands before infinite possibilities and chooses the one most fitting for him — here lies the first hint of relativism against Spinoza’s determinism. The subject’s content and essence are defined by force — an inner power that transfers the subject between its temporal states. Human passions and emotions shift according to these states, and each change is already contained within the concept, yet becomes actual only through this inner power. For Leibniz, this metaphysical force has no boundary; hence, the subject can comprehend the moral and aesthetic laws of nature.
“Their perfection appears when we contemplate them as they are in themselves, even if we disregard their external relations with their surroundings.”
Every divine act contains purpose and beauty — a perfect contribution to universal truth. The subject should align his will with reason and moral intention, thus rejoicing in his contribution to the objective good, the beautiful, and the harmonious whole — “the success of good designs.” His happiness lies in the finalities of his actions, in the balance between the diversity and abundance of the world and the simplicity of divine order:
“Through the soul or the form, there is a true unity corresponding to what in us is called the I.”
Such harmony cannot exist in artificial mechanisms nor in inert matter, no matter how complex. The subject, like the Monad, is unity and simplicity, whereas the object is filled with multiplicity. When nature fills itself with this simple spirit, it fills itself with life.
The truth of reason and intellect, the pulsating soul, man’s spiritual link to nature, the subject’s capacity to know itself and reality through its a priori faculties, the division of object and subject, the innate morality, divine goodness, reason as the primary source of knowledge, unity, perfection, the world containing its own logical order — all these characterize the rational subject.
And yet, despite the grandeur of this world and its luminous intellect, one who returns again and again to the meditations of the rationalist tradition gains not concrete understanding, but another abstraction — the unification of multiplicity under general concepts. Out of this critique emerged the empiricist camp — Locke and Hume — who sought to abandon the circular orbit of pure reason and descend straight into the solid ground of human nature itself. Only after conquering that ground could one ascend again to nature, science, and human life. From this moment, certainty would simply be.
“And it is clear that from this recognition arises the most complete idea of being, and the most perfect confidence in it.”
There is no advancing beyond experience — nor any need to. To do so, as in philosophies of “spirit,” is to guarantee one’s conclusions in advance. For David Hume, it is pointless to question the existence of bodies — it is self-evident to human reason. To test the effect of one body on another, one simply places them together and observes the result. The human soul, likewise, is no place for metaphysical speculation; it must be subjected to “rigorous and exact experiments,” just like the body. Experiment cannot proceed through metaphysical introspection, but only through physical introspection — through impressions: emotional sensations, subjective perceptions as they are felt. These impressions are the mind. There is no “self” existing apart from them; every time I look within, I encounter a particular perception — an emotion, a sense, a thought. When perception ceases, I cease as well:
“When I enter most intimately into what I call myself, I always stumble on some particular perception or other. I never can catch myself at any time without a perception, and never can observe anything but the perception.” (A Treatise of Human Nature)
The “I” of Hume, unlike that of Descartes, changes with the flux of human nature — it is not an eternal divine constant. Human impressions are in constant motion; with experience and maturity, perception and judgment shift. In daily life, man feels joy, pain, sorrow, pleasure — and these he feels throughout his body.
An idea, as a concept, is a faint impression derived from abstract, a posteriori thought — it cannot be the original datum. Impressions have force and vivacity; they are the source of ideas, dreams, imagination, which present sensations visually to the subject’s mind:
“All our simple ideas in their first appearance are derived from simple impressions, which they exactly represent.”
For man to grasp reality as complete, his spirit must not rely solely on outer impressions but also on inner empirical reflection. The conception of the world must arise from an active subject who perceives and conceptualizes consciously. Every idea man creates is an idea of being; the more vivid the impression, the more concrete the concept. I will smell jasmine or taste bread before I can imagine or recall them. The link between ideas constructs reality — relations of cause and effect. I cannot draw ideas from some parallel world or metaphysical presence; I can create only relative ideas — ideas of the natural. Beyond the perception of self, there is nothing to perceive. Man cannot move beyond himself — not by reason nor imagination. All thought, every yawn directed at a phenomenon, constitutes its existence.
“We are not accustomed to notice small changes,” says Hume.
The confusion between cause and its source, between idea, impression, and object — the same confusion Hume found in rationalism — is the very problem of induction. The human tendency to infer universal laws from habitual sequence is a dangerous habit. Every process, whether mental or material, is composed of a series of connected parts related by contiguity or resemblance, allowing easy passage from one idea to another:
“As this successive union is sufficient to make us ascribe identity to the whole, ’tis only a fiction of the imagination which renders these successive perceptions identical.”
If we observe carefully, we see that all phenomena change; even the smallest variation can destroy any notion of general identity or unity. The imagination of ideal continuity merely pretends to establish perfect law — much like Descartes’ mistake in believing the soul unchanging. Thus, Hume’s discussion of induction and causality reveals the metaphysical difficulty of defining personal identity:
“All the nice and subtle questions concerning personal identity are to be regarded rather as grammatical than as philosophical difficulties.”
For Hume, it is lived experience — not abstraction — that prevents us from falling into metaphysical chaos. The subject senses moral difference inwardly before he articulates it outwardly. He learns through experience what is good or evil, what brings pleasure or pain to body and mind:
“To find the moral quality, we must look within.”
External acts are only signs; their true moral content lies in the motive — in the natural human sentiment. There is no metaphysical duty here, only natural impulse. “Humanity,” he writes, “is itself the source of praise.” For every virtuous act, there are clear and distinct principles — “principles whose moral beauty makes the action praiseworthy.” Though external causes and temperament — selfishness, desire, material benefit — often burden the natural impulses of love, justice, and compassion, man still finds in his inner sentiment the measure of good.
The four thinkers discussed above — Descartes, Spinoza, Leibniz, and Hume — all developed distinct dialectics of the subject and his relation to the object, and each also maintained a parallel discourse on aesthetics, beauty, and art.
From Hume’s On the Standard of Taste, to Descartes’ letters to Marin Mersenne on beauty and music, to Spinoza’s moral analogies of beauty, and to Leibniz’s notion of artistic intuition in New Essays on Human Understanding — all reveal that the rational subject of the seventeenth century found artistic expression in what came to be known as Baroque art.
The Baroque (from the Portuguese Barocco, “irregular pearl”) stood as the artistic embodiment of the rational subject’s tension — his striving for infinity within order. Renaissance art had represented harmony, proportion, and perspective; the Baroque celebrated movement, excess, and the dramatic union of all arts. The static balance of representation was shattered into flowing forms seeking the infinite.
Heinrich Wölfflin illustrated this transformation through the difference between Raphael’s serene “Madonna” compositions and Rubens’ dynamic bodies, in which human figures merge with the total movement of the world — of animals, clouds, and earth. The unity of Spinoza’s monism appears here: man as a mode of God or Nature, struggling within the infinity of his desires.
Beyond the churches and royal halls, Baroque art also turned to the ordinary human being — the peasant, the worker, the domestic scene. Still life emerged as a meditation on mortality and sensuality: fruits, flowers, books, and knives placed beside signs of decay — skulls, rot, insects. The human subject, no longer divine but finite, became both creator and object of contemplation.
Through all this, art mirrored the rational subject’s awakening — his separation from his object (as Descartes taught), and his rediscovery of inner truth through creation. The aesthetic act became a meditation: in creating, man met the divine within himself. His art was no longer the imitation of perfection, but the expression of consciousness seeking its own certainty.
In Diego Velázquez’s Las Meninas (1656), this new subjectivity finds visual form. Multiple gazes intersect — the painter, the royal couple, the viewer — all observing and being observed. Reality becomes reflexive, a mirror of perception itself. As Leibniz wrote, “each substance is like a mirror of the universe.”
From the divine stillness of Raphael to the turbulent dynamism of Rubens and Caravaggio, from the perfect geometry of Descartes to the infinite substance of Spinoza — the seventeenth century produced not only the rational subject, but also the birth of his art.