Descartes' Error: Emotion, Reason, and the Human Brain

“But now I had before my eyes the coolest, least emotional, intelligent human being one might imagine, and yet his practical reason was so impaired that it produced, in the wanderings of daily life, a succession of mistakes, a perpetual violation of what would be considered socially appropriate and personally advantageous.”

This sentence demonstrates the limits of rationality as the ultimate instrument for good reasoning. Popular culture views emotions as hindering the decision-making process by obscuring rational thoughts. Here, Damasio challenges the status quo by offering a clinical counterexample to this popular philosophical belief.

“Even if a philosophical bent allowed one to think of the brain as the basis for the mind, it was difficult to accept the view that something as close to the human soul as ethical judgment, or as culture-bound as social conduct, might depend significantly on a specific region of the brain.”

This passage highlights how cultural norms and popular beliefs can hinder scientific reasoning and progress. Cartesian philosophy has so thoroughly separated the concept of the immortal spirit from the material body that it was difficult to imagine the brain playing a central role in regulating human behavior.

“Neither our brains nor our minds are tabulae rasae when we are born. Yet neither are they fully determined genetically.”

In this passage, Damasio offers a scientific answer to the nature-versus-nurture debate. Neurologically, genetics and experience each play a part in guiding the human mind. This fits in with the theory that the mind came evolutionarily after the body; the mind is an extension of a preexisting organism, and its function is to help the organism survive.

“The mind is embodied, in the full sense of the term, not just embrained.”

This quote reveals Damasio’s definition of the human mind. It is not confined to the cerebrum itself; its proper functioning depends on the peripheral nervous system as well. Damasio paints the human mind as a culmination of an extensive communication system that spans virtually all areas of the body.

“The picture I am drawing for humans is that of an organism that comes to life designed with automatic survival mechanisms, and to which education and acculturation add a set of socially permissible and desirable decision-making strategies that, in turn, enhance survival, remarkably improve the quality of that survival, and serve as the basis for constructing a person.” 

This important and revealing passage details the author’s outlook on what constitutes a human. First, it imagines the mind and the body as a unified organism. Cooperation between these two forces allows for better chances of survival during the process of evolution. Second, it paints the human mind as both dependent on genetic makeup and capable of improvement. Understanding Damasio’s outlook on the human mind and body as an integrated organism forged by the process of evolution later helps readers better understand his somatic-marker theory.

“The apparatus of rationality, traditionally presumed to be neocortical, does not seem to work without that of biological regulation, traditionally presumed to be subcortical. Nature appears to have built the apparatus of rationality not just on top of the apparatus of biological regulation, but also from it and with it.”

In this passage, Damasio challenges the conventional understanding of human rationality, which postulates that the neocortex regulates high reasoning, while all subcortical structures control only biological regulation. According to the author, this is false because the mind evolved from the body and therefore requires input from both neocortical and subcortical structures to function properly.

“In short, feeling your emotional states, which is to say being conscious of emotions, offers you flexibility of response based on the particular history of your interactions with the environment.”

This quote demonstrates the importance of being able to feel emotions in the decision-making process. Emotional states are a form of memory that can quickly and efficiently sway our decisions based on previous experience. However, patients with specific neurological conditions may not be able to feel these emotions. Damasio later explains that this likely contributes to their poor decision-making skills.

“The personal and immediate social domain is the one closest to our destiny and the one which involves the greatest uncertainty and complexity.”

This passage explains why patients who have damage to specific areas of the left frontal lobe of the brain can remain rational while being incapable of observing proper social behavior. The injury impairs their ability to relate emotional states to their inter- and intrapersonal actions, so they have difficulty predicting the immediate effect of their decisions in the highly volatile context of social relations.

“Somatic markers probably increase the accuracy and efficiency of the decision process. Their absence reduces them.”

This excerpt summarizes the theory that the previous passage proposes. Somatic markers, or emotion states that have been associated with specific stimuli, serve the dual purpose of streamlining the decision-making process.

“Invention is discernment, choice. […] Never in the field of his consciousness do combinations appear that are not really useful.”

This quote illustrates the automatic process through which the human brain discards options unworthy of consideration. For example, a mathematician attempting to figure out a problem does not reason through infinite possibilities but automatically discards impossible options without conscious input. Damasio uses this point to highlight the importance of bias in making quick and accurate decisions.

“From an evolutionary perspective, the oldest decision-making device pertains to basic biological regulation; the next, to the personal and social realm; and the most recent, to a collection of abstract-symbolic operations under which we can find artistic and scientific reasoning, utilitarian-engineering reasoning, and the developments of language and mathematics.”

This passage describes the numerous stages of development that the mind (as a device for decision-making) underwent through the ages. In humans, this broad understanding of the mind includes the central and peripheral nervous systems as well as the endocrine system. It began as a means for internal biological regulation and expanded to include the external environment. In humans, it further evolved to include high reasoning and abstract thoughts.

“Without basic attention and working memory there is no prospect of coherent mental activity, and, to be sure, somatic markers cannot operate at all, because there is no stable playing field for somatic markers to do their job.”

This quote highlights the importance of memory for the proper functioning of somatic markers. Lacking the capacity to recollect past data severely impairs the decision-making process, and emotional states cannot inform future decisions.

. “Where there is a need for order there is a need for decision, and where there is a need for decision there must be a criterion to make that decision.”

People can make an advantageous choice in a timely fashion only if they possess an inner criterion that influences their views. Although this passage does not specifically mention emotions, its purpose is to highlight the crucial role they play in biasing our views and expediting decision-making.

“Perceiving is as much about acting on the environment as it is about receiving signals from it.”

In this statement, Damasio unconventionally defines perception as a reciprocal action. It is instrumental both for understanding the external world outside the body and for acting on external influences during the decision-making process. This supports his somatic-marker hypothesis, which argues that the body and mind work in tandem to perceive and parse information.

“If ensuring survival of the body proper is what the brain first evolved for, then, when minded brains appeared, they began by minding the body.”

This is one of the most evocative and iconic passages in Descartes’ Error. It summarizes Damasio’s hypothesis, which argues that the mind evolved from the body. It also demonstrates why, logically, the mind and body work as a unified system.

“Mind is probably not conceivable without some sort of embodiment.”

This quote complements the previous one by asserting the body’s evolutionary precedence. Without a material body to regulate and protect, the evolutionary use for brains is hard to imagine. Cartesian philosophy, unfortunately, has no scientific basis. In other words, this quote succinctly illustrates why, in the context of evolution, a disembodied mind is difficult to explain.

“You cannot have a self without wakefulness, arousal, and the formation of images, but technically you can be awake and aroused and have images formed in sectors of your brain and mind, while having a compromised self.”

This passage tackles the difficult subject of selfhood in relation to the brain. Damasio argues that biological structures such as the brain can process somatic markers and other types of body states even when the individual’s selfhood or independence is lost. The purpose of this passage is to emphasize the invisibility of certain debilitating conditions.

“The metaself construction I envision is purely nonverbal, a schematic view of the main protagonists from a perspective external to both.”

In this quote, Damasio defines the concept of the metaself as a third-party image of an organism’s body and mind from an external perspective. It argues that language is unnecessary for consciousness or self-consciousness.

“For us then, in the beginning it was being, and only later was it thinking.”

This passage reiterates the precedence of the body over the mind in the evolutionary process. It supports the idea that mind and body are interconnected—and that considering them as a single organism may yield a more accurate picture of human cognition.

“Versions of Descartes’ error obscure the roots of the human mind in a biologically complex but fragile, finite, and unique organism; they obscure the tragedy implicit in the knowledge of that fragility, finiteness, and uniqueness.”

This quote emphasizes the negative social impact of the Cartesian notion of mind/body duality. It paints the mind (or spirit) as stout and entirely unaffected by the material world, when the spirit is, in fact, fragile and breakable. The Cartesian view can deprive patients with invisible neurological conditions from sympathy and social support structures.

“From my perspective, it is just that soul and spirit, with all their dignity and human scale, are now complex and unique states of an organism.”

Damasio anticipates the social backlash that his theory on the embodied mind may trigger. In this sentence, he argues that accepting the spirit’s materiality and fragility is possible without compromising its complexity and uniqueness.

“Perhaps the most indispensable thing we can do as human beings, every day of our lives, is remind ourselves and others of our complexity, fragility, finiteness, and uniqueness.”

This passage is, in a way, the philosophical conclusion to the somatic-marker hypothesis. Damasio’s hypothesis on the embodied mind highlights the fragility of selfhood and human cognition. Therefore, preserving the humane qualities of life requires the acknowledgement of its finite and fragile nature.

“This book was written with the conviction that knowledge in general and neurobiological knowledge in particular have a role to play in human destiny.”

This passage reveals Damasio’s motive in writing Descartes’ Error. He passionately believes in the power of knowledge as a tool that can shape the future. In addition, he hints at his commitment to the field of neurobiology.