What Is It Like to Be a Bat?

“In so far as I can imagine this (which is not very far), it tells me only what it would be like for me to behave as a bat behaves.”

Nagel emphasizes the difference between imagining an experience and having an experience. While we may be able to mimic the behavior of a bat, we cannot know what it is like to see and be in the world as a bat. This distinction highlights the central thesis of Nagel’s essay— that there is a subjective aspect to experience that cannot be objectively analyzed or understood.

“It is difficult to understand what could be meant by the objective character of an experience, apart from the particular point of view from which its subject apprehends it.”

This quote underscores Nagel’s critique of reductionist approaches to understanding consciousness. Nagel suggests that removing the subjective viewpoint from experience strips it of its essence, challenging the philosophical notion that experience can be completely understood objectively.

“But fundamentally an organism has conscious mental states if and only if there is something that it is like to be that organism.”

Here, Nagel establishes his definition of consciousness. He asserts that consciousness is intrinsically linked to subjectivity, that an organism is conscious if it experiences the world in a particular way. This positions consciousness as a deeply personal and individual phenomenon.

“For if the facts of experience—facts about what it is like for the experiencing organism—are accessible only from one point of view, then it is a mystery how the true character of experiences could be revealed in the physical operation of that organism.”

Nagel attempts to illustrate the perceived gap between subjective experience and objective physical reality. He suggests that understanding the physical operations of an organism (like a bat) might not reveal the true nature of its experiences, as experiences are inherently subjective.

“At present we are completely unequipped to think about the subjective character of experience without relying on imagination.”

Nagel acknowledges the current limitations of our understanding regarding the relationship between the physical and the mental, or between brain activity and subjective experience. He highlights the unresolved problem of mind-body dualism.

“Reflection on what it is like to be a bat seems to lead us, therefore, to the conclusion that there are facts that do not consist in the truth of propositions expressible in human language.”

Nagel proposes that certain truths or experiences are beyond human language’s reach. This underscores the limitations of the human-centric perspective and the inherent difficulty of understanding the consciousness of other creatures.

“The fact that we cannot expect to ever accommodate in our language a detailed description of Martian or bat phenomenology should not lead us to dismiss as meaningless the claim that bats and Martians have experiences fully comparable in richness of detail to our own.”

Nagel confronts the constraints of human understanding and language, arguing that just because we cannot perfectly articulate the subjective experiences of bats or hypothetical Martians does not mean their experiences are any less complex than ours. He suggests that our inability to comprehend nonhuman experiences fully does not equate to their insignificance or lack of depth. Essentially, Nagel advocates for acknowledging subjective consciousness across different species, despite our limitations in understanding.

“And to deny the reality or logical significance of what we can never describe or understand is the crudest form of cognitive dissonance.”

Nagel critiques the tendency to dismiss or deny the reality of experiences and phenomena beyond human capacity to describe or understand, labeling it as a form of cognitive dissonance. He implies that an intellectually honest approach would acknowledge the existence and significance of experiences, such as those of a bat, even if they elude our current understanding or linguistic abilities. Essentially, Nagel emphasizes the importance of humility and open-mindedness in our quest for knowledge and the not allowing our limitations to distort our perception of reality.

“It is not analyzable in terms of any explanatory system of functional states, or intentional states, since these could be ascribed to robots or automata that behaved like people though they experienced nothing.”

Nagel argues that consciousness and subjective experience cannot be reduced to “functional states.” He suggests that these could be replicated in nonconscious entities like robots, highlighting the distinctiveness of conscious experience and the difficulty of capturing it through objective analysis.

“Usually, when we are told that X is Y we know how it is supposed to be true, but that depends upon a conceptual or theoretical background and is not conveyed by the ‘is’ alone.”

Nagel underscores the importance of context, conceptual understanding, and theoretical frameworks in making sense of statements of equivalence, such as “X is Y.” He points out that the simple use of the word “is” does not convey the whole meaning or the “how” of the equivalence; instead we rely on our existing knowledge and understanding to interpret such statements. Essentially, Nagel highlights language’s limitations when devoid of relevant conceptual background, such as in the case of subjective experience.

“At the present time the status of physicalism is similar to that which the hypothesis that matter is energy would have had if uttered by a pre-Socratic philosopher.”

Nagel suggests that physicalism—the belief that everything is physical or can be reduced to physical phenomena— is somewhat premature or underdeveloped, comparable to the idea of matter being energy if proposed by a pre-Socratic philosopher. He implies that, much like the early Greek philosophers who lacked the scientific understanding to fully grasp the nature of energy, contemporary thinkers may not yet have the tools to comprehend or validate physicalism. Nagel is skeptical towards reductionist approaches in understanding consciousness, emphasizing the flummoxing nature of conscious experience.

“Suppose a caterpillar is locked in a sterile safe by someone unfamiliar with insect metamorphosis, and weeks later the safe is reopened, revealing a butterfly. If the person knows that the safe has been shut the whole time, he has reason to believe that the butterfly is or once was the caterpillar, without having any idea in what sense this might be so.”

Nagel uses a metaphor, where something is compared to something else without the use of “like” or “as.” In this case, he uses a caterpillar’s metamorphosis to a butterfly as an illustrative challenge to physicalism—the view that physical processes can explain all phenomena. He demonstrates how the physical transformation from caterpillar to butterfly can be observed and verified yet not understood, highlighting the limitations of a physicalist perspective.

“The problem is unique. If mental processes are indeed physical processes, then there is something it is like, intrinsically, to undergo certain physical processes.”

This quote presents the paradox at the heart of Nagel’s argument and the problem of consciousness itself. If mental processes are physical, there should be a way to understand them objectively. However, Nagel maintains that the subjective nature of these processes resists such understanding.