HARNAD:¬†¬†¬†¬†Yep, the “hard problem” is to explain how and why sentient organisms FEEL rather than just DO. It’s exactly the same problem as explaining how and why there could not be a T3 or T4 zombie. Where does the definition of the “hard problem” come from? I know Dave Chalmers named it, but who described the problem? And exactly why is it a problem?


The “hard problem” of consciousness was coined and articulated by philosopher David Chalmers in 1995. It refers to the issue of explaining the nature of our subjective experiences, or why certain physical processes in the brain are accompanied by an experienced inner life. These subjective experiences are also referred to as “qualia.”

The “hard problem” is distinguished from the “easy problems” of consciousness, which include explaining the ability to discriminate, integrate information, report mental states, focus attention, etc. Even though these problems are far from “easy” in the practical sense, there is a clear path to understanding them in terms of computational or neural mechanisms. Hence, Chalmers termed them “easy”.

The “hard problem”, on the other hand, is deemed hard because it doesn’t seem amenable to such explanation. The question “why does the feeling which accompanies awareness exist at all?” appears to resist those methods that we conventionally use in science to explain phenomena.

This is because, typically, science proceeds by finding a mechanism that performs the function in question. For example, we can explain a car’s movement by referencing the mechanism of its engine. However, when it comes to consciousness, it’s not clear that finding a mechanism that ‘performs’ consciousness, in the sense of the ability to have subjective experience, would actually provide the kind of explanation we’re looking for.

It’s not sufficient to find neural correlates of consciousness, or to find information processing structures in the brain that mirror our conscious experiences. That would still leave a gap in our understanding – why should these physical processes give rise to subjective experience? Why aren’t we, as philosopher Thomas Nagel has put it, just mindless automata, acting without experiencing?

This is the crux of the hard problem – it’s not merely asking for a mechanism, but an explanation of why certain physical processes give rise to subjective experience, something that seems fundamentally non-physical.

HARNAD:    I have no idea what “non-physical” means, do you? (I understand cognitive science but not metaphysics.)  But I do know what unexplained (or unexplainable) means. I know Chalmers named it, but who described the hard problem?


Sorry for any confusion. The “hard problem” of consciousness was indeed first named and extensively discussed by David Chalmers. He used the term “non-physical” to refer to subjective experiences, or “qualia”, which seem fundamentally different from the kinds of things that physical science deals with. In other words, we can describe and predict the behavior of physical entities like atoms, electrons, and neurons, but subjective experiences do not seem to behave like physical entities in the same way.

Thomas Nagel’s 1974 paper “What is it like to be a bat?” also touched upon this issue prior to Chalmers. Nagel argued that an organism has conscious mental states “if and only if there is something that it is like to be that organism‚ÄĒsomething it is like for the organism.”

So, while Chalmers might have been the one to name the “hard problem” and bring it to the forefront of contemporary philosophical discussion, the basic issue of explaining subjective experience has a much longer history in the philosophy of mind, dating back at least to Descartes’ dualist distinction between mind and body in the 17th century.

However, it’s important to note that not everyone agrees there is a “hard problem” – some argue that once we solve the so-called “easy problems” of consciousness (i.e., explaining the mechanisms behind cognitive and behavioral functions), what we think of as the “hard problem” might not seem so problematic. This perspective, however, is a matter of ongoing debate in the field.

HARNAD:¬†¬†¬†¬†The “easy problem” is explaining how and why organisms can DO what they can do. (That’s what we’ve been discussing here as reverse-engineering T3 and T4). The “hard problem” is explaining how and why (sentient) organisms can FEEL. If we forget about the meaningless notion of “nonphysical,” why is the hard problem still so much harder than the easy problem?


The difficulty with the “hard problem”, as compared to the “easy problem”, arises from the inherently subjective and qualitative nature of feelings or experiences, also known as “qualia”. While we can objectively observe, measure, and describe physical processes and behaviors, we cannot directly access someone else’s subjective experiences in the same way.

For example, we can understand and describe the physical processes associated with seeing the color red‚ÄĒlight hitting an object, reflecting into our eyes, being processed by our visual systems, leading to a particular cognitive and behavioral response. This is the kind of problem that can be solved with enough empirical research and is hence termed the “easy problem”.

However, understanding why these processes are accompanied by a subjective experience of “redness” is much more difficult. Why isn’t the physical process of seeing color “like” anything at all? Why is it that we have a qualitative, subjective experience of the color red, rather than just a cognitive recognition and behavioral response? These are the questions posed by the “hard problem”.

Many theories have been proposed to address this, from various forms of physicalism that posit some yet-undiscovered physical explanation for consciousness, to dualism that suggests consciousness might be a separate entity from the physical world, to panpsychism that proposes that consciousness is a fundamental aspect of the universe, like space and time. But so far, no theory has been able to fully bridge the gap between the objective physical world and the subjective world of experience, leading to what Chalmers calls the “explanatory gap”.

There’s also the challenge of “other minds” in philosophy‚ÄĒwhile you can directly experience your own consciousness, you can’t directly experience someone else’s. All our knowledge about other minds is inferred from behavior and communication, but we have no way to directly observe their subjective experiences. This inherent limitation compounds the difficulty of the “hard problem”.

HARNAD:    If we chuck out the weasel-words again, as well as the metaphysical non-solutions. The hard problem is to explain, causally, how and why anything that organisms can DO should FEEL like anything at all. Feeling is real, but without a causal explanation it seems superfluous.


Yes, that’s indeed a clear and concise framing of the hard problem of consciousness. The issue is trying to explain why and how subjective experiences arise from objective physical processes – or in other words, how and why certain processes are accompanied by an internal, subjective “feeling”.

Objective behaviors and actions can be causally explained by physical processes, such as neuronal activity, chemical reactions, and interactions with the environment. We can trace the causes and effects, build models, and make predictions. These explanations fit within our current scientific framework, which deals with observable, quantifiable phenomena.

However, when it comes to subjective experiences or feelings, our current scientific methods fall short. We don’t yet have a way to objectively measure or quantify these experiences, and we don’t have a clear understanding of how they could be causally produced by physical processes. This is why some people consider consciousness to be a “non-physical” phenomenon.

It’s not that feelings are superfluous or unnecessary. Rather, they’re central to our existence as sentient beings. The challenge is figuring out how to account for them within our scientific understanding of the world. The hard problem of consciousness is essentially about bridging this explanatory gap. How can we expand our scientific methods and theories to account for the subjective, qualitative aspects of existence, and to uncover the causal mechanisms that give rise to them? That is the challenge that faces researchers in fields such as cognitive science, neuroscience, and philosophy of mind.

HARNAD: When ChatGPT palses intp starts echoing the empty weasel-words of the field it’s time to give the topic a break…

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