Stop and think for a moment about what makes you human. Is it your ability to solve complex math problems? Your capacity to feel love and compassion? The fact that you can imagine tomorrow or remember yesterday? Maybe it’s your thumb—that opposable digit that lets you grip tools? Or perhaps it’s something deeper, something you can’t quite put your finger on but feel in your bones? Here’s the wild part: philosophers have been wrestling with this exact question for over 2,500 years, and they still haven’t reached a consensus. What does it mean to be human? What is “man” in the philosophical sense? (And yes, we’ll address why philosophy traditionally used “man” rather than “human” or “person.”) This isn’t just academic navel-gazing—understanding what makes us human shapes everything from how we treat each other to what rights we believe people deserve, from medical ethics to artificial intelligence debates. When we ask “what is man?”—or more inclusively, “what is a human being?”—we’re asking one of the most profound questions imaginable: What are we, really? Are we just clever animals? Souls trapped in bodies? Meaning-making machines? Accidents of evolution? Divine creations? The answer you give shapes your entire worldview, your ethics, your politics, your sense of purpose. So buckle up, because we’re about to dive into one of philosophy’s oldest, deepest, and most consequential questions.
What Is “Man” in Philosophy?
Let’s start with the basics, then we’ll dig into the complications (and there are many). In philosophy, the term “man” has traditionally referred to human beings in general—not specifically males, but humanity as a whole. Modern philosophy increasingly uses “human being,” “person,” or “humanity” to avoid confusion and be more inclusive, but you’ll encounter “man” constantly in philosophical texts, especially older ones.
Biologically speaking, humans belong to the species Homo sapiens (and more precisely, the subspecies Homo sapiens sapiens). We’re primates, mammals, vertebrates, animals. That’s straightforward enough. But philosophy asks deeper questions: What distinguishes us from other animals? What’s our essence? What makes human life meaningful or valuable?
The Classic Definition: Rational Animal
The most influential definition in Western philosophy comes from Aristotle, who defined humans as “rational animals” (in Greek, zoon logon echon, literally “living being having reason”). This definition dominated Western thought for over two millennia and still shapes how we think about humanity today.
Let’s unpack what Aristotle meant. Humans are animals—we share biological needs, instincts, bodily functions with other creatures. We eat, sleep, reproduce, seek pleasure, avoid pain, just like other animals. We have bodies that get sick, age, and die. We’re not angels or gods floating above material existence—we’re embodied, biological beings.
But humans are rational animals—we possess something Aristotle called nous (intellect or reason) that sets us apart. We don’t just experience the world; we reflect on it, analyze it, understand abstract concepts, plan for distant futures, contemplate hypotheticals, grasp universal principles. We ask “why?” We seek truth. We make arguments. We build knowledge systematically.
This capacity for reason, for Aristotle, is humanity’s defining characteristic and highest function. Just as the function of a knife is to cut and a good knife cuts well, the function of a human is to reason, and a good human reasons well—cultivating intellectual and moral virtues through rational reflection.
Aristotle also famously called humans zoon politikon—”political animals” or “social animals.” We’re not solitary creatures but naturally form communities, cities (polis), and engage in collective life. Language, for Aristotle, is key here—we’re the animals with speech (logos), which allows us to communicate not just feelings (which animals do) but ideas about justice, the good, right and wrong. This capacity for reasoned discourse makes political life possible.
Why This Definition Mattered
Aristotle’s definition wasn’t just abstract theorizing—it had profound practical implications that shaped Western civilization:
It established reason as humanity’s highest faculty. If reason defines us, then cultivating rationality through education, philosophy, and science becomes central to human flourishing. Intellectual virtues matter.
It implied ethical standards. If humans are rational by nature, then living according to reason is living according to our nature—which for ancient and medieval thinkers meant living ethically. Irrationality, giving in to passions without rational control, meant falling short of humanity’s potential.
It justified social and political hierarchies. Here’s where things get troubling. Aristotle and later thinkers used this definition to argue that those deemed less rational—women, enslaved people, “barbarians”—were somehow less fully human or naturally subordinate to rational men. The definition became a tool for oppression, justifying horrific inequalities.
It shaped religious thought. When Christianity adopted Aristotelian philosophy (especially through Thomas Aquinas), the rational soul became the image of God in humans, what makes us special in creation, and what survives bodily death.
It influenced science and technology. If reason is humanity’s essence, then developing tools and methods to extend our reasoning capacity—logic, mathematics, scientific method, computers—becomes a fundamentally human project.
The Mind-Body Problem: Are We Souls or Bodies?
One question that’s haunted philosophy since ancient Greece: Are humans fundamentally physical bodies, or are we something else—souls, minds, consciousness—temporarily inhabiting bodies? This mind-body problem shapes how philosophers define humanity.
Plato’s Dualism: The Soul Is the Real You
Before Aristotle, his teacher Plato proposed a radical answer: You are your soul, and your body is just a temporary vehicle you’re stuck with during earthly life.
For Plato, the soul is immaterial, eternal, and divine—it existed before your birth and will exist after your death. The body, by contrast, is material, mortal, and prison-like. Plato famously compared the soul to a charioteer trying to control two unruly horses (the rational part controlling spirited and appetitive parts), or to a pilot steering a ship (the body).
This view has intuitive appeal. When you introspect, you encounter thoughts, feelings, consciousness—mental stuff that seems very different from flesh and bones. You can imagine your mind existing separately from your body (in heaven, as a ghost, uploaded to a computer). Your body changes constantly—cells die and regenerate, you age, you might lose limbs—yet “you” seem to persist. So maybe the real you is something non-physical?
Plato’s dualism profoundly influenced Christianity and Islam, which adopted the idea of an immortal soul separate from the mortal body. It shapes how many people still think about themselves today—we say things like “I have a body” rather than “I am a body,” implying body and self are separate.
Aristotle’s Alternative: Unity of Soul and Body
Aristotle rejected his teacher’s dualism, proposing instead that soul and body are inseparable—two aspects of one unified substance, like matter and form.
For Aristotle, the soul (psyche) isn’t a separate thing inhabiting the body but rather the form, organization, or functioning of a living body. Your soul is what makes your body alive and gives it capacities—nutrition and growth (vegetative soul, which plants have too), perception and locomotion (animal soul, which animals share), and reason (rational soul, unique to humans).
Think of it this way: What makes a knife a knife isn’t the metal (matter) alone but the knife-shape and knife-function (form). Similarly, what makes a human body human isn’t just the flesh (matter) but the human-form and human-functions—especially rationality. The soul is the body’s animating principle, not a ghost inside the machine.
This view implies that soul and body can’t exist separately—when the body dies, the soul ceases too (though Aristotle hedges on whether the purely intellectual part might be immortal). There’s no “you” apart from your embodied existence. You’re not a soul trapped in a body; you’re a rational animal—a psychophysical unity.
Medieval Christianity: Synthesizing Plato and Aristotle
Christian theology faced a challenge: Plato’s dualism fit nicely with belief in immortal souls and afterlife, but Aristotle’s philosophy became dominant in medieval universities. How to reconcile them?
Boethius (480-524) offered an influential synthesis, defining a person as “an individual substance of a rational nature”—emphasizing both substantiality (you’re a real, unified thing) and rationality (reason defines you). The soul and body form one substance, not two separate things, but the rational soul survives death.
Thomas Aquinas (1225-1274) developed this further. Following Aristotle, he argued soul and body form one substance—the soul is the form of the body. But incorporating Christian belief, he argued the rational soul is a subsistent form—it can exist temporarily without the body after death, awaiting resurrection when soul and body reunite. Humans are properly soul-body unities, and both body and soul matter for who we are.
This view became Catholic orthodoxy: You’re not a ghost temporarily inhabiting a meat-suit, nor are you just a body without a soul. You’re a unified person, body and soul together, and both are essential to your humanity. Your body isn’t a prison or embarrassment—it’s part of God’s good creation, which is why resurrection of the body (not just immortality of souls) matters in Christian eschatology.
Descartes’ Dualism: Ghost in the Machine
In the 17th century, René Descartes revived a radical dualism that influenced modern philosophy profoundly.
Descartes famously doubted everything he could possibly doubt, searching for certain knowledge. He concluded: “I think, therefore I am” (Cogito, ergo sum). Even if I’m deceived about everything else, the fact that I’m thinking proves I exist. But what is this “I”? Descartes answered: a thinking thing (res cogitans)—pure consciousness, immaterial mind.
For Descartes, mind and body are completely different substances with opposite natures:
Mind (res cogitans): Immaterial, thinking, conscious, indivisible, not located in space. This is the real you—your thoughts, feelings, will, consciousness.
Body (res extensa): Material, extended in space, mechanical, divisible, unconscious. Your body is basically a biological machine that mind somehow interacts with.
This is often called the “ghost in the machine” view (though that phrase was coined by critic Gilbert Ryle in the 20th century). You’re essentially a ghost (immaterial mind) operating a machine (mechanical body) through some mysterious interaction point (Descartes suggested the pineal gland).
Cartesian dualism has problems that philosophers have been pointing out for centuries: If mind and body are completely different substances, how do they interact? How does your immaterial will cause your material hand to move? How do physical events in your brain cause mental experiences? The “interaction problem” has never been satisfactorily solved.
Yet something like Cartesian dualism remains intuitively compelling for many people. When you introspect, consciousness seems obviously real and seemingly different from physical matter. Near-death experiences, out-of-body experiences, and religious beliefs in afterlife all seem to presuppose something like a separable soul. The mind-body problem remains live and contentious in philosophy of mind today.
The Enlightenment and Modern Developments
As Europe moved through the Enlightenment and into modernity, new questions and approaches to understanding humanity emerged.
Kant: The Autonomous Rational Subject
Immanuel Kant (1724-1804) transformed philosophy’s understanding of humanity by emphasizing autonomy and moral agency as central to human nature.
For Kant, humans exist in two realms simultaneously:
The phenomenal realm is the world of appearances accessible to experience and scientific investigation. As phenomenal beings, we’re part of nature—physical organisms subject to natural laws, causation, and determinism. Science can study us empirically.
The noumenal realm is the world of things-in-themselves, beyond possible experience. As noumenal beings, we’re free, autonomous agents capable of moral action. We can act according to reason and moral law rather than just responding to natural causes. This freedom is beyond scientific investigation—we can’t observe it empirically, but we must presuppose it to make sense of morality.
What makes humans special, for Kant, is our capacity for practical reason—the ability to recognize and act according to moral principles derived from reason alone, not just responding to desires or consequences. We can ask “What should I do?” and answer through rational reflection on universal moral principles (the categorical imperative), then act accordingly despite contrary inclinations.
This capacity for autonomous moral action gives humans dignity—inherent worth that demands respect. Humans are ends in themselves, never merely means to others’ ends. We can’t be used like tools or treated like things because we’re rational agents with our own purposes and inherent value.
Kant’s philosophy profoundly influenced human rights discourse, liberal political theory, and modern ethics. The idea that humans have inherent dignity deserving respect—regardless of wealth, status, ability, or usefulness—became foundational to modern moral and political thought.
The Rise of Scientific Approaches
As natural sciences developed, new approaches to understanding humanity emerged that challenged traditional philosophical definitions:
Evolution transformed human self-understanding. Darwin showed humans evolved from earlier primates through natural selection, sharing common ancestry with apes. We’re not separately created with special divine essence—we’re animals that gradually developed distinctive traits over millions of years. This made the question “what makes humans special?” much more complicated. Is it degree (we have more intelligence, more complex language) or kind (something qualitatively different)? How do you draw a sharp line when evolution is gradual and continuous?
Psychology began studying human behavior, cognition, and development scientifically. Freud emphasized unconscious drives, making humans less purely rational than Enlightenment thinkers assumed. Behaviorists tried reducing mental states to observable behaviors. Cognitive scientists modeled minds like computers. Neuroscience sought to explain consciousness through brain activity. All these approaches studied humans empirically rather than through pure philosophical reflection.
Anthropology revealed enormous cultural diversity in how different societies understand human nature, morality, gender, social organization, and meaning. What seems “naturally human” in one culture isn’t universal—maybe there’s no single fixed human nature but many ways of being human shaped by culture?
Sociology emphasized how social structures and relationships shape individual identity and behavior. Maybe humans are fundamentally social beings constituted by relationships, not autonomous individuals?
These scientific approaches raised the question: Do we still need philosophical definitions of humanity, or can science tell us everything important about what we are?
20th Century: Philosophical Anthropology Emerges
In response to scientific reductionism and traditional metaphysics, a new discipline emerged in early 20th century Germany: philosophical anthropology.
What Is Philosophical Anthropology?
Philosophical anthropology is the branch of philosophy that makes the question “What is the human being?” its central focus. It attempts to understand humanity philosophically while incorporating insights from biology, psychology, sociology, and anthropology.
Unlike scientific disciplines that study specific aspects of humans (biology studies bodies, psychology studies minds, sociology studies societies), philosophical anthropology asks about humanity as a whole—what unifies all these aspects? What makes humans distinctive? What’s our place in nature and cosmos?
The discipline formally emerged in 1920s Germany with several key thinkers who revolutionized how we think about human nature.
Max Scheler: Humans as Spirit
Max Scheler (1874-1928) is often credited with founding philosophical anthropology through his 1928 work Man’s Place in the Cosmos (Die Stellung des Menschen im Kosmos).
Scheler asked: What distinguishes humans from animals? Previous answers focused on intelligence, tool use, language—but research kept showing animals have versions of these too. Apes use tools. Birds have complex communication. Dolphins show sophisticated intelligence. So what’s unique to humans?
Scheler’s answer: spirit (Geist)—the capacity to transcend immediate drives and environments, to say “no” to instinct, to contemplate abstract ideals and values beyond survival needs. Animals are bound to their drives and immediate environments. Humans can step back, reflect, pursue truth for its own sake, act according to ideals and values even against self-interest, imagine alternatives to what is.
Humans aren’t just smarter animals. We’re world-open rather than environment-bound. We can consider reality as a whole, ask fundamental questions about existence and meaning, create art and culture, pursue knowledge without practical benefit, sacrifice ourselves for abstract ideals. This spiritual dimension—not supernatural souls but the capacity for transcendence and meaning-making—sets humans apart.
Importantly, Scheler emphasized that humans are both biological organisms driven by vital impulses and spiritual beings capable of transcendence. We’re not pure spirits trapped in bodies (Platonic dualism) or just complex animals (reductionism). We’re unique beings combining biological nature with spiritual capacities in tension with each other.
Helmuth Plessner: Eccentric Positionality
Helmuth Plessner (1892-1985) developed a sophisticated account of human uniqueness based on how we relate to our bodies and world.
In his major work Levels of Organic Life and the Human (1928), Plessner distinguished three forms of “positionality”—ways organisms relate to their environment:
Plants have open positionality—they’re not centralized, lack boundaries between self and environment, simply grow and assimilate from surroundings.
Animals have centric positionality—they have centralized organization (a body with boundaries), sense-perception creating inside/outside distinction, and are positioned in their environment. But animals are simply their positionality—they experience from a perspective but don’t reflect on that perspective.
Humans have eccentric positionality—we’re both centered (have a perspective, a body, a position) and decentered (can step outside our perspective, reflect on ourselves from the outside, see ourselves as objects). We’re simultaneously subject and object to ourselves.
This creates a unique human situation. We experience ourselves immediately from inside (like animals) but also can view ourselves from outside, as others see us. We live in our bodies but also stand outside them reflecting on them. We’re in the present moment but also constantly transcending it through memory and anticipation.
This eccentric positionality explains distinctly human phenomena: self-consciousness (we don’t just experience; we know we’re experiencing), embarrassment (we see ourselves from others’ perspectives), concern with appearance (we care how we appear because we can imagine outside views), historical consciousness (we situate ourselves in larger temporal contexts), and the human predicament of never being fully at home—we’re always slightly outside ourselves, questioning, reflecting.
Arnold Gehlen: Deficiency and Culture
Arnold Gehlen (1904-1976) took a more biological approach, arguing humans are unique among animals in being biologically incomplete or deficient.
Most animals are born with specialized adaptations and instincts that allow them to survive in specific environments. Birds have wings for their ecological niche. Fish have gills. Wolves have predatory instincts. But humans? We’re born helpless, with no instincts for specific environments, no specialized physical adaptations, incredibly long development periods, unable to survive independently.
We’re what Gehlen called “deficient beings” (Mängelwesen)—compared to other animals, we’re pitifully weak, slow, vulnerable, lacking natural weapons or defenses. We should have gone extinct.
But this deficiency is paradoxically our strength. Because we lack specialized instincts and adaptations, we’re world-open—adaptable to virtually any environment, able to learn rather than relying on fixed instincts, capable of modifying environments rather than just adapting to them.
How do we survive despite our biological inadequacy? Through culture and institutions. We create tools, language, technology, social organizations, traditions, knowledge systems that compensate for our biological deficiencies. Culture is humanity’s artificial second nature—it provides the structure and stability that instincts provide animals.
For Gehlen, understanding humans requires understanding both our biological nature (deficient, unspecialized, world-open) and our cultural nature (the institutions and systems we create to survive). We’re the animals that must create culture to exist at all.
Existentialism and Phenomenology
While philosophical anthropologists focused on humanity’s place in nature, existentialists and phenomenologists explored human existence from the inside—what it feels like to be human, how we experience and make meaning in the world.
Heidegger: Dasein and Being-in-the-World
Martin Heidegger (1889-1976) revolutionized how philosophy thinks about human existence with his 1927 work Being and Time (Sein und Zeit).
Heidegger rejected traditional ways of defining humans (rational animal, thinking substance, etc.) as missing something fundamental. Instead of asking “what is man?” he asked about human existence or being-there (Dasein—literally “being-there” or “being-here”).
What’s distinctive about human existence? We’re the beings for whom our own being is an issue. We don’t just exist; we care about our existence, question it, interpret it, project possibilities for ourselves. We’re not simply present-at-hand like rocks or even animals; we exist in relation to possibilities, concerns, and meanings.
Heidegger emphasized that humans are fundamentally “being-in-the-world”—not isolated subjects confronting external objects, but always already embedded in meaningful contexts. We exist in relationships, situations, cultural worlds, before we ever reflect or theorize. Understanding, care, and engagement with world come before detached contemplation.
Our existence is also fundamentally temporal. We’re not timeless substances but temporal beings stretched between past (where we come from, what we’ve been), present (what we’re currently engaged with), and future (possibilities we project). We exist as projects, always ahead of ourselves, never fully complete until death.
This means humans are characterized by radical finitude and anxiety. We’re thrown into existence without choosing to exist, facing an uncertain future, heading inevitably toward death. This creates existential anxiety—not fear of specific threats but fundamental unease about existence itself. How we respond to this anxiety—authentically facing it or fleeing into distraction and conformity—shapes our existence.
Heidegger’s analysis shifted philosophy from defining human essence abstractly to exploring concrete structures of human existence phenomenologically—how we actually live, experience, and make meaning.
Sartre: Existence Precedes Essence
Jean-Paul Sartre (1905-1980) developed existentialism in a more accessible direction, emphasizing radical freedom and responsibility.
Sartre’s famous claim: “Existence precedes essence.” For manufactured objects, essence precedes existence—a paperweight is designed with a purpose (essence) before being made (existence). But humans are different. We exist first, then create our essence through choices and actions. There’s no pre-defined human nature or purpose. We’re radically free to make ourselves whatever we choose.
This freedom is both exhilarating and terrifying. We’re “condemned to be free”—whether we like it or not, we must choose, and we’re responsible for those choices. We can’t blame God, human nature, circumstances, or society for who we become. Every moment demands a choice, and we alone bear responsibility.
Many people flee this freedom through “bad faith”—self-deception, pretending we’re not free, hiding behind roles and identities (“I’m just a waiter, I have no choice but to act this way”), blaming circumstances, conforming to social expectations without reflection. But this is inauthentic—denying the freedom that defines human existence.
Authentic existence means acknowledging your freedom, accepting responsibility, making committed choices despite the absence of pre-given meaning, and creating yourself consciously rather than passively accepting what others or society dictate.
Contemporary Questions and Challenges
In the 21st century, the question “what is a human being?” takes on new urgency as developments in science and technology challenge traditional boundaries.
Cognitive Science and Neuroscience
Brain science reveals that our conscious experience, decisions, emotions, and sense of self all correlate with specific neural activity. Does this mean we’re “just” our brains? That consciousness is “nothing but” neural firing? That free will is an illusion?
These questions trouble people because they seem to reduce human uniqueness to physical mechanisms. If neuroscience can explain consciousness fully, what happens to the soul? To human dignity? To moral responsibility?
But many philosophers argue this is a false dichotomy. Understanding the neural basis of consciousness doesn’t eliminate consciousness or make it less real, any more than understanding how hearts work eliminates blood circulation. We can acknowledge humans are physically embodied beings whose mental life depends on brains while still recognizing that human experience, culture, meaning, and values are real and important phenomena not reducible to neuron firings.
Artificial Intelligence
As AI systems become more sophisticated, exhibiting creativity, learning, problem-solving, and even seemingly conversing intelligently, we face unsettling questions: Could AI become conscious? Could artificial beings be “persons”? What would that mean for humanity’s supposed uniqueness?
If intelligence, language, creativity, and learning—traditionally considered distinctly human—can be replicated artificially, what’s left that’s special about us? Are we just biological computers that could in principle be replicated in silicon?
These questions force us to clarify what we think makes humans special. Is it intelligence per se, or something about biological embodiment? Emotional depth? Consciousness? Moral agency? Self-awareness? The capacity for authentic relationships? Different answers lead to different conclusions about whether AI could ever truly be “human-like” in morally significant ways.
Enhancement and Transhumanism
Biotechnology, genetic engineering, brain-computer interfaces, and other technologies raise possibilities of radically enhancing human capacities or even transcending biological humanity altogether. “Transhumanists” embrace this possibility, advocating technological enhancement to overcome human limitations.
This raises deep questions: Is there a human nature we should preserve, or are we legitimately self-creating beings who should enhance ourselves without limits? Would dramatically enhanced humans (vastly more intelligent, longer-lived, stronger) still be human in any meaningful sense? Would creating “post-humans” be progress or loss?
These aren’t just science fiction scenarios—gene editing, neural implants, and life extension technologies are developing rapidly, forcing us to decide what we want humanity’s future to look like.
Animal Cognition
Research continually reveals that animals have more sophisticated cognitive and emotional capacities than previously thought. Apes use tools and have culture. Elephants mourn their dead. Dolphins have names. Crows solve complex problems. Octopuses show intelligence despite radically different nervous systems. Pigs are smarter than dogs and toddlers.
This complicates the question of human uniqueness. Every trait once thought exclusively human—tool use, language, culture, self-recognition, future planning, morality—appears in some form in other animals. The difference is degree more than kind, which challenges philosophical definitions based on rational or linguistic capacities as human essence.
This has ethical implications too. If animals have sophisticated minds and rich emotional lives, how can we justify treating them as mere resources for human use? The more we recognize continuity between human and animal minds, the harder it becomes to justify the moral chasm we typically assume between “us” and “them.”
Why This Question Still Matters
You might wonder: Why do we need philosophical definitions of humanity when science can study humans empirically? Here’s why the philosophical question remains important:
Science describes; philosophy evaluates. Science tells us what humans are like—our biology, psychology, behavior. But it doesn’t tell us what makes human life valuable, what we ought to do, how we should treat each other, what kind of life is worth living. Those are philosophical and ethical questions requiring normative reflection, not just empirical observation.
Self-understanding shapes identity and action. How you conceive human nature affects everything—your ethics, politics, sense of purpose, relationships, priorities. If you think humans are primarily rational, you’ll emphasize education and argument. If you think we’re primarily emotional, you’ll focus on empathy and connection. If you see humans as naturally selfish, you’ll design institutions differently than if you see us as naturally cooperative.
The question has practical consequences. Debates about abortion, euthanasia, animal rights, AI rights, enhancement technologies, human dignity, and countless other practical issues all hinge on what we think humans are and what makes us special. The philosophical question isn’t abstract—it’s urgent and practical.
It’s inherently reflexive. When humans ask “what are we?” we’re exercising the very capacities that might define us—self-reflection, conceptual thinking, meaning-making. The question is part of the answer. Maybe what makes us human is precisely that we’re the beings who ask this question.
FAQs About “Man” in Philosophy
Why does philosophy use “man” instead of “human” or “person”?
The term “man” in philosophical contexts traditionally referred to humanity in general, not specifically males, though this usage is increasingly replaced by more inclusive language. The word comes from Latin homo (human being) and Greek anthropos (human), both gender-neutral terms referring to humanity as a whole. However, this generic use of “man” has always been problematic because it easily conflates with “man” meaning male, and philosophical texts written by men often made assumptions about rationality, agency, and human nature that reflected male experience while excluding or marginalizing women. Modern philosophy increasingly uses “human being,” “humanity,” “human,” or “person” instead, recognizing that supposedly universal definitions of “man” often weren’t truly universal but reflected particular (often privileged male European) perspectives. When you encounter “man” in older philosophical texts, it officially means “human,” but it’s worth asking whether the definition really encompasses all humanity or just some humans. The language choice matters because it shapes whose experiences and capacities count as definitive of human nature.
What’s Aristotle’s definition of a human being?
Aristotle defined humans as “rational animals” (Greek: zoon logon echon, literally “living being having reason”)—beings who share biological animal nature but are distinguished by the capacity for rational thought. This definition dominated Western philosophy for over 2,000 years and still influences how we think about humanity. For Aristotle, humans aren’t just smarter animals; rationality (nous or intellect) is our defining essence and highest function. We don’t just perceive and react instinctively like other animals; we reflect, understand universal principles, grasp cause and effect, contemplate abstract concepts, and deliberately reason about what to do. Aristotle also called humans zoon politikon (political or social animals) because we naturally form communities and cities, and we’re the only animals with speech (logos) that allows us to communicate not just feelings but ideas about justice, good, and right—making political life possible. This definition emphasized reason as humanity’s highest capacity and implied that cultivating rational and moral virtues through education and philosophy was essential to human flourishing. However, Aristotle problematically used this definition to justify hierarchies, arguing those he deemed less rational (women, enslaved people, non-Greeks) were naturally subordinate.
What is the mind-body problem?
The mind-body problem asks how mental states (thoughts, feelings, consciousness) relate to physical states (brain, body)—are they the same thing, different things, or somehow both? This problem has haunted philosophy since ancient times because minds and bodies seem very different. Your body is physical, material, located in space, visible to others, subject to physical laws. Your mind—your consciousness, thoughts, feelings—seems immaterial, private, not obviously located anywhere physical, not directly observable by others. So what’s their relationship? Dualism (Plato, Descartes) claims mind and body are separate substances—you’re essentially a non-physical mind or soul temporarily connected to a physical body. Materialism or physicalism claims only physical stuff exists—mental states are identical to or emerge from brain states, not separate things. Property dualism claims there’s only physical substance, but it can have both physical and mental properties. Idealism claims only mental/spiritual reality is fundamental—the physical is derivative. The “interaction problem” troubles dualism: if mind and body are completely different, how do they interact? How does your immaterial decision cause your material hand to move? Materialists face the “hard problem of consciousness”: how do physical brain processes produce subjective conscious experience? The mind-body problem remains unresolved, with profound implications for free will, personal identity, artificial intelligence, and afterlife beliefs.
What is philosophical anthropology?
Philosophical anthropology is the branch of philosophy that makes “What is the human being?” its central question, attempting to understand humanity comprehensively by integrating philosophical reflection with insights from biology, psychology, sociology, and cultural anthropology. Unlike scientific disciplines studying specific aspects of humans (biology studies bodies, psychology studies minds), philosophical anthropology asks about humanity as a whole—what unifies all these aspects? What makes humans distinctive? What’s our place in nature and cosmos? The discipline formally emerged in 1920s Germany with thinkers like Max Scheler, Helmuth Plessner, and Arnold Gehlen who rejected both traditional metaphysical definitions (rational animal, thinking substance) as too abstract and scientific reductionism as missing essential dimensions of human existence. Philosophical anthropology explores questions like: What distinguishes humans from animals? Are we defined by rationality, language, culture, self-consciousness, or something else? How do biological nature and cultural/spiritual dimensions relate? What does it mean to live a human life? The discipline remains relevant today as developments in neuroscience, artificial intelligence, genetic engineering, and animal cognition force us to reconsider what makes humans unique and what being human means in a rapidly changing world.
Why did Descartes think mind and body are separate?
René Descartes argued mind and body are completely different substances based on what seemed like clear logical differences between them. Descartes’ famous method of doubt led him to conclude “I think, therefore I am”—even if everything else is uncertain, the fact that he’s thinking proves he exists as a thinking thing. But what is this thinking thing? Descartes observed that mind (res cogitans, “thinking substance”) is characterized by consciousness, thought, no extension in space, indivisibility (you can’t divide consciousness into parts), and privacy (only you access your thoughts directly). Body (res extensa, “extended substance”) is characterized by occupying space, having dimensions and location, divisibility (you can divide bodies into parts), and public observability (others can see and measure bodies). These seem like opposite natures—if mind isn’t spatial and body isn’t conscious, how could they be the same thing? Descartes concluded they must be different substances somehow interacting. He suggested the pineal gland as the interaction point, though he couldn’t explain the mechanism. This “Cartesian dualism” faces the notorious “interaction problem”—if mind and body are completely different, how do they causally interact? How does your immaterial will move your material arm? Despite this problem, dualism remains intuitively appealing because consciousness seems obviously different from physical matter when we introspect.
What makes humans unique according to philosophical anthropology?
Philosophical anthropologists proposed various features distinguishing humans from other animals, though what exactly makes us unique remains debated. Max Scheler argued humans uniquely possess “spirit” (Geist)—not supernatural souls but the capacity to transcend immediate drives and environments, to say “no” to instinct, to pursue ideals and values beyond survival, to contemplate reality as a whole. We’re “world-open” rather than environment-bound. Helmuth Plessner emphasized “eccentric positionality”—humans don’t just experience from a perspective (like animals); we can step outside our perspective, reflect on ourselves as objects, see ourselves from outside. We’re simultaneously centered and decentered, subject and object to ourselves. Arnold Gehlen argued humans are uniquely “deficient beings”—unlike specialized animals with instincts for specific environments, we’re born helpless, unspecialized, lacking instinctual programming. This deficiency makes us world-open and forces us to create culture and institutions as our “second nature.” Common themes: self-consciousness (awareness of being aware), language and symbolism (complex communication beyond immediate needs), culture and tradition (transmitting knowledge across generations), world-openness (not bound to specific environments or instincts), and meaning-making (asking “why?” and creating significance). However, research showing sophisticated animal cognition complicates claims about human uniqueness—the differences may be more of degree than kind.
Are humans born with a fixed nature or do we create ourselves?
This question divides philosophers profoundly. Essentialists argue humans have a fixed nature or essence—certain universal characteristics defining what we are (like rationality for Aristotle). This nature exists prior to any individual human and determines what counts as flourishing or living well for our kind. Understanding human nature guides ethics and politics—we should create conditions allowing humans to fulfill their nature. Existentialists like Sartre argue the opposite: “existence precedes essence”—we exist first without predetermined nature, then create our essence through free choices and actions. There’s no fixed human nature constraining us; we’re radically free to make ourselves whatever we choose. Trying to define human nature is “bad faith”—self-deception that denies our freedom. Middle positions acknowledge both: we’re born with certain biological constraints and capacities (not everything is possible—we can’t fly by flapping our arms) but have significant freedom to shape ourselves within these constraints. Culture, history, and individual choices dramatically shape what we become, but not infinitely—we’re neither blank slates nor fully determined by nature. Contemporary science reveals: genes influence but don’t determine behavior; brains have plasticity allowing change; culture profoundly shapes psychology; yet some constraints are biological. Most philosophers today reject both pure essentialism (fixed unchanging nature) and pure existentialism (total self-creation), recognizing humans are complex beings whose nature involves both biological givens and cultural/individual malleability.
What did Kant mean by human dignity?
Kant argued humans have inherent dignity—absolute, unconditional worth demanding respect—because we’re rational autonomous agents capable of moral action according to universal principles derived from reason. This dignity isn’t earned through achievement, intelligence, virtue, or usefulness—it’s intrinsic to all rational beings simply by virtue of their rational nature. Why does rationality confer dignity? Because rational beings can recognize moral laws through reason, understand universal principles, and freely choose to act according to moral duty rather than just following desires or instincts. We’re autonomous—self-governing according to reason—not just responding mechanically to causes. This makes us ends in ourselves, never merely means to others’ ends. Kant’s famous categorical imperative formulation: “Act in such a way that you treat humanity, whether in your own person or in the person of any other, never merely as a means to an end, but always at the same time as an end.” You can’t use people like tools because they’re autonomous rational agents with their own purposes deserving respect. This grounds human rights and moral equality—all rational beings have equal dignity regardless of intelligence, ability, wealth, status, or utility to others. Even criminals retain dignity (though their rights may be limited as consequence of crimes). Kant’s concept profoundly influenced human rights discourse, liberal political theory, and bioethics. It provides philosophical foundation for claims that humans have inalienable rights and inherent worth independent of social recognition or usefulness.
How does culture relate to human nature?
The relationship between culture and human nature is complex and much-debated. One view sees culture as expressing or developing a pre-existing biological human nature—we have certain innate capacities and drives that culture channels and develops in various ways, but underlying human nature remains constant across cultures. Another view sees culture as constituting human nature—we become human through enculturation, learning language and norms and practices that make us who we are. Humans raised without culture (feral children) don’t develop normal human capacities, suggesting culture is essential to human nature, not just added on. Arnold Gehlen’s synthesis is influential: humans are biologically “incomplete” or “deficient beings”—unlike animals with instincts for specific environments, we’re born helpless without instinctual programming. This biological openness makes culture necessary. Culture is humanity’s “second nature”—institutions, traditions, knowledge systems that provide the structure instincts provide animals. We can’t survive without culture; it compensates for our biological inadequacy. So culture and nature aren’t opposed but interdependent. Contemporary anthropology reveals enormous cultural diversity in psychology, cognition, values, social organization—suggesting culture profoundly shapes what seem like “natural” human traits. Yet all cultures share commonalities (language, family structures, moral systems, art) suggesting biological constraints on cultural variation. Most scholars today reject nature versus nurture dichotomy, recognizing humans are biocultural beings whose nature involves both biological capacities and cultural development inseparably intertwined.
What’s the connection between defining humanity and ethics?
How you define human nature profoundly shapes ethical conclusions about how humans should live and treat each other. If humans are essentially rational (Aristotle), then human flourishing involves developing intellectual virtues through education; ethics emphasizes reason guiding action; and those deemed less rational might be considered less fully human (problematically justifying oppression). If humans are free autonomous agents (Kant), then respecting human dignity means respecting autonomy; ethics emphasizes rights, consent, and not using people merely as means; paternalism is suspect. If humans are social/relational beings (Aristotle’s “political animal”), then ethics emphasizes community, relationships, and common good over pure individualism; isolation is seen as unhealthy or unnatural. If humans are biologically determined, then moral responsibility becomes problematic—can we blame people for behavior their biology drives? If humans have no fixed nature but create themselves (Sartre), then ethics is about authentic self-creation and freedom; there’s no human telos or natural purpose to guide ethics. If humans are continuous with animals, this challenges the moral chasm often assumed between humans and nonhumans, potentially extending moral consideration to animals. Bioethical debates illustrate these connections: defining when human life begins (abortion), ends (euthanasia), or what counts as human dignity (enhancement) all depend on what you think makes us human and valuable. Your anthropology—theory of human nature—isn’t separate from your ethics; it’s foundational to it.
How have scientific developments challenged philosophical definitions of humanity?
Modern science has profoundly challenged traditional philosophical definitions in multiple ways. Evolution showed humans evolved gradually from other primates through natural selection—we’re not separately created with special essence but animals that developed distinctive traits over millions of years. This makes sharp boundaries between human and animal questionable and challenges ideas about fixed human nature given for all time. Neuroscience correlates consciousness, decisions, emotions, personality with specific brain activity, suggesting mental life depends entirely on physical brains. This challenges substance dualism (separate immaterial souls) and raises questions about free will if decisions have neural causes prior to conscious awareness. Psychology revealed unconscious drives (Freud), cognitive biases, situation’s power over behavior (social psychology), challenging views of humans as purely rational deliberative agents. Anthropology documented enormous cultural diversity in cognition, values, gender conceptions, social organization, child development—what seems “naturally human” varies dramatically, challenging universal definitions. Animal cognition research shows sophisticated intelligence, culture, language, self-recognition, theory of mind, even apparent morality in other species, undermining claims these are uniquely human. Artificial intelligence exhibits creativity, learning, problem-solving, conversation previously thought uniquely human, raising questions whether AI could be conscious or whether human cognition is just complex computation. These developments don’t eliminate philosophy’s role—science describes what is but doesn’t determine what ought to be, and questions about meaning, value, dignity require normative reflection beyond empirical observation. But science forces philosophy to take biology, neuroscience, and empirical facts seriously when defining humanity.
