Introduction
You live in an intellectual culture dominated by materialist naturalism. This mainstream worldview assumes that everything in the universe can be explained by physical science. Yet you likely find that this orthodox view leaves out conscious experience, the capacity for rational thought, and objective moral values.
Thomas Nagel argues that the standard materialist consensus is inadequate and false. Modern neo-Darwinian evolutionary theory, combined with physical reductionism, cannot account for the emergence of mind, reason, and value in a purely physical world.
The book investigates these failures across three core domains. You will examine the nature of subjective consciousness, the validity of cognitive thought, and the reality of moral values.
- How can physical matter generate subjective experience?
- Why does reason allow you to discover objective truths?
- Are moral values real features of the natural order?
1. Antireductionism and the Natural Order
Reductive materialism is an unsupported world picture that fails to explain consciousness, requiring an antireductionist view where mind is central to nature.
The mind-body problem is not merely a local issue concerning living organisms. It is an overarching question that invades your understanding of the entire cosmos and its history. Physical sciences and evolutionary biology cannot be insulated from the problem of consciousness. A true appreciation of this difficulty must eventually change your conception of the role that physical sciences play in describing the natural order.
Reductive materialism is widely assumed by scientists and philosophers to be the only serious possibility for explaining the natural order as a whole. Yet it remains an unsupported overarching world picture. This comprehensive speculative world picture posits a hierarchical relation among the specialized sciences and assumes the completeness in principle of an explanation of everything through their unification. However, most practicing scientists do not rely on this specific cosmological answer in their day-to-day research.
The Limits of Materialism
It is highly implausible that life and its evolutionary history are merely the result of physical accidents and natural selection without additional teleological principles. You face common-sense incredulity regarding the standard neo-Darwinian account. It questions the probability that self-reproducing life forms could spontaneously emerge from dead matter via physics and chemistry alone, and whether accidental genetic mutations could supply enough viable variations over geological time.
The intricacy of fireplaces, nucleotide sequences, and phenotypes presents severe probability problems for orthodox reductionist biology. The origin of the genetic code resists probability explanations based on physical law alone. Furthermore, accounting for the evolution of complex features like the eye requires an adequate supply of viable mutations rather than unproblematic assumptions.
Richard Dawkins imagines a sequence of gradually evolving phenotypes as if their appearance through DNA mutations were unproblematic for the evolution of the eye.
The empirical arguments against orthodox reductionism raised by critics and defenders of intelligent design deserve serious attention rather than professional scorn. Writers like Michael Behe, Stephen Meyer, and David Berlinski highlight real probability problems with the orthodox reductive view regarding the origin of life and evolutionary history. While the author does not accept the design alternative or possess a sensus divinitatis, he believes these iconoclasts challenge an unassailable scientific dogma that treats reductionism as sacrosanct.
Objective Idealism and Natural Teleology
The failure of psychophysical reductionism points toward neutral monism and an antireductionist view that makes mind central to the natural order.
If psychophysical reductionism fails, physical science cannot account for consciousness and value. If mind is an integral product of biological evolution, biology cannot be purely physical science. This opens the door to a world view where mind is a basic aspect of nature.
The intelligibility of the world implies an objective idealist perspective where rationality is at the root of the natural order. Science relies on the foundational assumption that the world is intelligible. The author aligns with a tradition of objective idealism, suggesting that nature gives rise to conscious beings with minds because the universe is inherently comprehensible to such beings.
Both materialism and theism fail to provide a complete, reassuring transcendent self-understanding of human cognitive and normative capacities. Theism places intelligibility outside the world via an intentional creator, abandoning a self-contained natural order. Conversely, evolutionary naturalism applies biological explanations that ultimately undermine confidence in your own cognitive faculties and moral realism by tying belief-formation strictly to survival advantage.
You should seek an expanded, non-reductionist naturalistic understanding that explains life, consciousness, and reason as inherent consequences of the internal order of the natural world. The appearance of conscious organisms, perception, and normative reasoning must have been inherent in the universe and early life long before animals evolved. A satisfying explanation would show that these developments were a significant likelihood rather than mere accidents or results of external divine intervention.
Past thinkers have proposed non-reductionist or teleological models of evolution that parallel the need for a natural order directed toward mind. C.D. Broad described non-mechanistic possibilities in The Mind and Its Place in Nature in 1925, and Henri Bergson proposed creative evolution driven by a universal vital force in L'évolution créatrice in 1907.
2. Consciousness
The modern mind-body problem originated in the seventeenth-century scientific revolution led by Galileo and Descartes. Galileo and Descartes established a conceptual division by defining physical science through mathematically precise, quantitative descriptions of spatiotemporal primary qualities like shape, size, and motion. Subjective appearances, secondary qualities such as color and sound, and human intentions were excluded from objective physical reality and assigned to the mind.
The seventeenth-century scientific revolution created the mind-body problem, and standard materialist theories fail to explain subjective experience.
Theories like conceptual behaviorism, causal behaviorism, and functionalism attempt to reduce mental states to observable behavioral conditions, dispositions, or causal roles in controlling organism-environment interactions. These theories miss the essential first-person inner mental state, such as how sugar tastes or red looks, which goes beyond mere behavioral responses.
The psycho-physical identity theory proposed that mental events are brain events, but it struggles because the mental-physical relation appears contingent rather than necessary. Proposed by U. T. Place and J. J. C. Smart in the 1950s as a scientific hypothesis rather than a conceptual truth, the theory posits that mental event Ψ equals physical brain event Φ. Unlike necessary theoretical identities such as water equals H2O, brain states do not inherently necessitate subjective experience, raising the question of what makes Φ also Ψ without appealing to nonphysical properties. Water equals H2O, where physical properties alone are sufficient for water without requiring anyone to observe or taste it.
Historical Roots and Failure of Behaviorism
If psychophysical reductionism is false, standard materialist evolutionary theory cannot explain the appearance of conscious organisms. A purely physical evolutionary theory can explain physical adaptation and complex central nervous systems through natural selection and genetic variation over three billion years. However, it leaves subjective consciousness completely unexplained, treating it as an inexplicable extra brute fact or a mysterious side effect unless the evolutionary account incorporates psychophysical principles.
A conjunctive explanation fails to explain an outcome unless there is an internal relation between the causes and the result. Typing 3, +, 5, and = into a pocket calculator produces 8 due to underlying physical causes, but this does not explain why the device produced the right arithmetic answer without referencing the algorithm and the designer's intention. Similarly, a physical evolutionary history combined with a nonhistorical psychophysical theory leaves consciousness as an accidental and unexplained concomitant unless an internal psychophysical relation governs the entire process.
Constitutive and Historical Explanations
The constitutive account of how complex systems are mental must be either emergent or reductive. An emergent account links complex physical functioning to mental states through higher-order principles without altering the physical nature of basic elements, though it can still feel like magic. A reductive account posits that elementary constituents of the universe possess protomental properties that explain both physical and mental character when combined, leading to a form of panpsychism or neutral monism.
The historical account of how conscious organisms arose must take one of three forms:
- a causal historical account;
- a teleological account;
- an intentional account.
Historical accounts can rely on efficient causation through elementary properties, invoke non-purposive natural teleological laws of self-organization toward complexity, or appeal to intentional divine intervention. Secular theories are restricted to causal efficient mechanisms or natural teleology, though both present major obscurities. Human consciousness is permeated with intentionality, the capacity to represent the world and aims through perception, belief, desire, and action. Because these elements resist psychophysical reduction, a utopian long-term goal for research should seek a unified naturalistic form of understanding where organisms are seen as expressions of both the physical and mental character of the universe.
3. Cognition
Higher-level cognitive capacities like logical reasoning and scientific thought enable humans to transcend subjective appearance and discover objective reality, a feat that defies reductive physicalism.
Logical reasoning and scientific thought transcend subjective appearance and objective reality in ways that defy reductive physicalism.
While basic perceptual consciousness can be fitted into an evolutionary framework, the faculty of reason is different. When you make logical inferences or recognize contradictions, you respond to objective norms that do not derive their authority from biological origins.
Driving south in the early morning and seeing the sun rise on the right, you recognize that this observation contradicts your belief because the earth rotates in a specific direction.
Any evolutionary or naturalistic account of reason necessarily presupposes the validity of reason itself, making circular any attempt to validate reason through evolutionary origins. You cannot step back from a logical inference to confirm it by reflecting that evolution selected your brain for accuracy. That very thought relies on prior logical judgments of consistency. Sharon Street argues that theoretical reason cannot be interpreted realistically if our reasoning capacities have an evolutionary explanation, maintaining realism about the natural world but antirealism about epistemic reasons.
Unlike perceptual consciousness, which might theoretically be analyzed through protomental elements, reason is a holistic property of a fully formed conscious mind and cannot be reduced to miniature rationality atoms. Comparing the mind to a computer built from transistor-like homunculi fails because it accounts only for behavioral output while omitting the understanding of content and grounds essential to reason. Nagel assumes for the sake of argument that an evolutionary version can accommodate consciousness, while acknowledging that Darwinian theory is intensely complex and debated internally.
The Space of Reasons
Physical law alone cannot explain the origin of life or make it expected, because blind physical forces have no inherent bias toward producing marvelous living creatures. Citing Roger White's work, Nagel notes that rejecting the chance hypothesis because life looks designed does not justify assuming a nonintentional physical bias. Physical law could favor any arbitrary outcome equally.
Natural Teleology and Origins
Nagel proposes natural teleology as a fourth alternative to chance, creationism, and directionless physical law, suggesting that nature contains irreducible developmental principles biased toward the marvelous. Natural teleology requires that the laws of physics leave successor states open with probability distributions, and that paths leading toward higher organizational complexity and value have significantly higher probabilities.
The emergence of human cognition represents an expansion of consciousness from isolated creaturely perspectives into an objective, world-encompassing form where the universe gradually becomes aware of itself. What began as a biological evolutionary process has become, through language and interpersonal communication, a collective cultural process that allows conscious subjects to grasp objective truth and value.
4. Value
Evaluative and moral realism posits that our responses try to reflect independent evaluative truths, whereas subjectivism argues that evaluative truth depends entirely on our motivational dispositions and responses.
Evaluative and moral realism posits objective truths that resist subjectivist and Darwinian explanations, pointing toward natural teleology.
Subjectivist and expressivist accounts, rooted in the Humean tradition, ground value judgments in psychological facts about human motivational dispositions like calm passions or moral sentiments. By contrast, a realist position holds that correct value judgments align with the actual structure and weight of values in the world, which are true in their own right rather than grounded in psychological facts.
Sharon Street argues that moral realism is incompatible with a Darwinian account of evolution because the ability to detect mind-independent moral truth contributes nothing to reproductive fitness.
While natural selection explains our motivational dispositions, the mind-independent truth of resulting value judgments has no role in the Darwinian story. This creates a disanalogy with factual and physical judgments, where detecting external reality is crucial for survival.
Imagine humans evolving more like lions, where males have unreflective evaluative tendencies to experience killing unrelated offspring as demanded by circumstances, and females feel no strong tendency to hold it against them.
Basic experiences like pleasure and pain possess a double nature, serving adaptive biological functions while also holding objective intrinsic value that can be recognized by practical reason.
From a Darwinian perspective, aversion to pain enhances fitness because it leads us to avoid injury, rendering the real badness of pain superfluous. However, realists argue that pain and pleasure have positive and negative value in themselves beyond their adaptive roles, serving as clear examples through which we encounter real value.
The Historical Emergence of Value
Value realism requires consciousness to play an active, non-epiphenomenal role in the world, allowing humans to be motivated directly by the recognition of reasons and judgments.
Human action is explained not merely by physiology or basic desires, but by judgment-sensitive attitudes. When someone acts to relieve another person's headache with aspirin, the action is explained by the recognition that headaches are bad and that this ordinary fact counts in favor of the action, involving a conscious control of action and free will.
The historical origin of value requires expanding the natural order because value enters the world with life, and practical reason emerges as a higher development of conscious nature.
Value is pluralistic and as rich as the variety of forms of life. Entities from bacteria to conscious animals have a good, and self-conscious beings eventually evolve who can recognize values and respond to reasons. This historical emergence of value and practical reason cannot be accounted for by standard materialist naturalism or accidental side effects of natural selection.
To account for the appearance of life, consciousness, and value, we may look to natural teleology as an alternative to purely nonteleological physical and chemical laws.
A natural teleology hypothesis suggests that the natural world possesses a cosmic predisposition to give rise to complex forms, conscious agents, and life because life is a necessary condition for the instantiation and recognition of value. This offers an alternative to improbable flukes, divine intervention, or pure chemical evolution.
Contingent normative truths, such as linguistic norms, depend on collective human responses and historical drift.
Nagel notes that while he leaves aside contingent normative truths, he recognizes that changing language and internalized norms create strong personal convictions of correctness that are products of a contingent set of linguistic rules.
Nagel observes everyday linguistic shifts in publications like the New York Times, where words like disinterested are increasingly used to mean uninterested.
10 Key Ideas
- Modern reductive materialism is an unsupported overarching world picture that fails to explain consciousness, requiring an antireductionist view where mind is central to nature.
- The intricacy of biological features presents severe probability problems for orthodox reductionist biology, making it highly implausible that life and evolution are merely the result of physical accidents and natural selection without additional teleological principles.
- The failure of psychophysical reductionism points toward neutral monism and an antireductionist view that makes mind central to the natural order through an objective idealist perspective where rationality is at the root of reality.
- The seventeenth-century scientific revolution created the mind-body problem by excluding subjective appearances from objective physical reality, and standard materialist theories fail to explain subjective experience.
- A purely physical evolutionary theory leaves subjective consciousness completely unexplained, treating it as an inexplicable extra brute fact or a mysterious side effect unless the evolutionary account incorporates psychophysical principles.
- The historical account of how conscious organisms arose must take a causal historical, teleological, or intentional form, seeking a unified naturalistic understanding where organisms are expressions of both the physical and mental character of the universe.
- Higher-level cognitive capacities like logical reasoning and scientific thought enable humans to transcend subjective appearance and discover objective reality, responding to objective norms that do not derive their authority from biological origins.
- Physical law alone cannot explain the origin of life or make it expected, because blind physical forces have no inherent bias toward producing marvelous living creatures.
- Nagel proposes natural teleology as a fourth alternative to chance, creationism, and directionless physical law, suggesting that nature contains irreducible developmental principles biased toward the marvelous.
- Evaluative and moral realism posits that our responses try to reflect independent evaluative truths, pointing toward natural teleology where the natural world possesses a cosmic predisposition to give rise to complex forms, conscious agents, and life.