As Above,so Below? The Limits of Evolutionary Considerations for Supporting Hypotheses About Consciousness

Abstract

On a traditional top-down experimental approach to consciousness science, researchers start by investigating consciousness in humans, or closely related living animals, based on evidence from experimental paradigms that aim to directly disentangle conscious from unconscious processing. Only afterward are these insights (iteratively) extended beyond the human case to investigate and understand how consciousness is distributed more broadly. In A Philosophy for the Science of Animal Consciousness, Walter Veit radically departs from this approach by taking a Copernican turn in suggesting that we should first understand consciousness’ simple beginnings, and only afterward make sense of how these humble beginnings further complexified. Central to Veit’s approach is abruptly removing the reliance on insights about human consciousness by suggesting that evolutionary considerations can provide a credible source of evidence that can independently and directly support hypotheses about consciousness. My aim here is two-fold. Firstly, I will argue that using evolutionary considerations to support hypotheses about consciousness this way is problematic for principled reasons. The consequence is that evolutionary considerations fail to convincingly support Veit’s central hypothesis: That consciousness’ function is to enable organisms to deal with high pathological complexity. However, secondly, I will suggest that these considerations can nevertheless support an adjacent hypothesis: That an evaluative mode of being is required in general to deal with high pathological complexity irrespective of how consciousness is involved. Taken together, I conclude that consciousness science should not be turned upside down, and that Veit’s central hypotheses are better understood as hypotheses not directly concerned with consciousness.

Introduction

In A Philosophy for the Science of Animal Consciousness, Veit (2023a) motivates a need for what we may describe as a Copernican shift in consciousness science. ¹ Specifically, a central aim of Veit’s book is to urge consciousness researchers, as Veit nicely puts it, to:

“[T]ransition toward a true Darwinian science of consciousness in which the evolutionary origin, function, and phylogenetic diversity of consciousness are moved from the field’s periphery to its very centre and enable us to endogenize consciousness into an evolutionary view of life” (Veit, 2023a, p. 1).

The book is engaging and contributes to what is, in my mind, one of the most well-developed and compelling explications, and defenses, of a bottom-up evolutionary (BE) approach to scientifically studying consciousness so far. ² Moreover, not only does Veit develop a methodology for studying consciousness, the cherry on top is that he also puts it to use to motivate hypotheses about the origin (i.e., consciousness arose during the Cambrian explosion), function (i.e., that the function of consciousness is to enable animals to deal with high pathological complexity), and nature (i.e., consciousness is fundamentally associated with a particular evaluative system that utilizes [valenced] consciousness as a common currency). All in all, then, I think Veit’s work comprises an important contribution to an ongoing debate about how we should scientifically study consciousness.

I agree with many of the suggestions Veit makes throughout the book. For example, I agree with Veit’s suggestions that (1) evolutionary considerations should play a more prominent role in consciousness science, ³ that (2) investigating what animals are conscious of, ⁴ instead of only investigating that they are conscious whatsoever ⁵ is important and deserves more attention, and that (3) a comprehensive understanding of consciousness, including its (phylogenetic) distribution and humble beginnings, cannot solely rely on insights about human consciousness.

Despite this, I remain unconvinced that consciousness science needs the kind of Copernican shift that Veit is advocating for. There are several reasons for this. First, I ultimately think that the conventional top-down experimental (TE) approach (see below) can accommodate all of these points without having to adopt the central tenets of the BE-approach, and I think the TE-approach can fend of many of the criticisms Veit levies against it, including the idea that the TE-paradigm suggests that consciousness is not amenable to a gradualist and evolutionary treatment (de Weerd, in preparation-a; de Weerd & Dung, 2025). Second, Veit claim that the that the distinct (empirical and theoretical) resources he appeals to are uniquely positioned to make progress on (1) narrowing the explanatory gap (Veit, 2023a, p. 42), as well as (2) making progress on questions about consciousness’ function, distribution, and origins. I think the BE-approach is ultimately unsuccessful on both counts.

Elsewhere I extensively engage with (1), ultimately suggesting that the various “gap-closing” moves suggested by BE-proponents are unconvincing (de Weerd, in preparation-b). ⁶ I will focus here, however, exclusively on (2). Specifically, the aim is two-fold. First, I will explicate, and elaborate on, a significant problem for the BE-approach that Leonard Dung and I have posed (de Weerd & Dung, 2025). This problem, as we will see, puts significant pressure on (2). The problem, in a nutshell, is that it is unclear for principled reasons how the kind of bottom-up evolutionary considerations Veit appeals to supports (i.e., make more plausible) Veit’s pathological complexity thesis (PCT), that the function of consciousness is to enable animals to deal with high pathological complexity. ⁷

Second, I will tentatively suggest that Veit’s PCT is perhaps better understood not as a hypothesis about consciousness specifically, but instead as a hypothesis about the need for an evaluative mode of being simpliciter to deal with high pathological complexity in general (call this PCT*). I will suggest that whilst the evidence Veit appeals to fails to convincingly make a case for the PCT, said evidence seems to more convincingly support the PCT*.

Let’s start unpacking all of this.

The TE-and-BE-Approaches to Consciousness Science

Consider first the traditional approach to consciousness science that Veit is juxtaposing his own approach against. Articulating this approach will be helpful in understanding the limitations of the BE-approach.

Most consciousness researchers adopt a TE-approach according to which we should first gain at least a tentative understanding of consciousness in humans or closely related animals, based on experimental paradigms in laboratory settings, before we can start working our way backwards to understand consciousness beyond the human case (see also Michel, 2019, for a historical overview). To put it in a suggestive slogan: According to the TE-approach we can only understand consciousness’ past if we understand it in the presence. More specifically, the TE-approach consists of (at least) the following key aspects.

First, most consciousness researchers endorse deep realism (Shevlin, 2024), the view according to which consciousness constitutes a genuine natural kind which can only be inferred from, and is not entailed by, behavior and cognitive capacities, nor is consciousness straightforwardly entailed by the physical properties that capture this natural kind.

Second, TE-proponents assume that we should start by investigating human consciousness because verbal introspective reports from humans (and ocassionally nonverbal reports from monkeys or apes) provide a clear, initial and defeasible, source of evidence about whether a given stimulus is consciously experienced or not (Michel, 2023). Specifically, TE-proponents have developed various experimental paradigms to disentangle conscious from unconscious processing, which include binocular rivalry (Blake & Logothetis, 2002), masking (Kouider & Dehaene, 2007), dichotic listening (Brancucci & Tommasi, 2011), and conditions (see Shevlin, 2021). Experimental paradigms that go beyond introspective reports, such as no-report paradigms, are also used, though they remain controversial (see e.g., Block, 2019; Michel & Morales, 2020) and are still ultimately validated (or should be combined with) subjective reports from humans (Overgaard & Fazekas, 2016).

Third, the empirical evidence gathered with these paradigms are subsequently used to develop, or support, scientific theories of consciousness, which posit various mechanisms to account for the difference between conscious and unconscious processing, such as global broadcasting, perceptual reality monitoring, integrated information, and so on (for a detailed overview see Seth & Bayne, 2022). As an alternative to this theory-driven approach, TE-proponents are increasingly using what is called an iterative natural kind reasoning approach (Mckilliam, 2024).

According to this approach, we take human introspective reports as our initial, defeasible, source of evidence and investigate which other capacities or neural signatures consistently cluster with introspective reports (e.g., trace conditioning, rapid reversal learning, and cross-modal learning [Birch, 2022]). Iteratively applying these clusters to new cases, such as various non-human animals allows for expanding the cluster of consciousness-related abilities/features, as well as correcting previous measures (for a detailed discussion see Mckilliam, 2024). Accordingly, this approach allows us to bootstrap our way out of only relying on subjective reports to detect consciousness, without having to rely on a specific theory of consciousness, but it still takes evidence from humans as its (inevitable) starting point (Bayne et al., 2024; Mckilliam, 2024).

So, how does Veit aim to diverge from this way of studying consciousness and why does he deem it necessary to do so? First, Veit does not seem to want to claim that the TE-approach fails to gain any traction on consciousness-related questions. As Veit puts it, theories produced by this TE-approach:

“However, while I have offered an alternative to views associating consciousness with later evolutionary innovations, such as rich forms of information integration or selfhood, this doesn’t mean proponents of such views must be entirely wrong. Indeed, I see it as a virtue of my account that their claims regarding a more recent dawn of consciousness may very well be re-conceived of instead as what Godfrey-Smith (omitted) has described as a transformation view as opposed to a latecomer view” (Veit, 2023, p. 119).

In other words, Veit seems to concede that the TE-approach may be successful—in principle—in unveiling various insights about the nature of human consciousness. However, Veit’s main problem is that TE-insights only capture various “experience-shaping traits” (Godfrey-Smith, 2020a, p. 209), traits which capture human-specific dimensions or particularities. The problem with this approach, Veit argues, is that they fail to get a grip on this more basic, primitive, form of experience that has later been transformed into complex human-like experiences. Accordingly, if researchers foundationally and primarily base their hypotheses about the nature and function of consciousness in general on insights about human consciousness, then they will inevitably be misled by confusing insights about human consciousnes for insights about consciousness in general, including minimal consciousness. Because of this, Veit suggests that:

“[A] truly Darwinian comparative approach cannot make the human case the model for all consciousness” (Veit, 2023, p. 116).

Consciousness, then, should not foundationally and primarily be studied in laboratory settings, focusing on humans, “under the conditions of highly constrained experiments” (Veit, 2023, p. 116). Instead, Veit aims to remedy this problem by abruptly removing the influence of insights about human consciousness by suggesting that hypotheses about the function and origin of (minimal) consciousness can be independently justified by various bottom-up evolutionary considerations:

“It is only by investigating the evolutionary origins of consciousness and the ecological lifestyles of these first conscious entities that we will truly understand the place of consciousness in nature without being misled by the particularities, idiosyncrasies, and complexities of the human mind” (Veit, 2023, p. xii).

More specifically, Veit reasons as follows. First, he claims that “[b]y making sense of the lifestyle changes of animals preceding the Cambrian explosion, we will be able to explain the dawn of subjective experience in the form of a basic feel of evaluation” (Veit, 2023, p. 23). In particular, Veit observes that the Cambrian explosion gave rise to an explosion of what he calls “pathological complexity,” which can be roughly thought off as the trade-off problem between competing actions that organisms could take to maximize their fitness during their lifecycles when facing various challenges and opportunities. Veit notes that even though all life forms face pathological complexity, the Cambrian explosion introduced various complex biological organizations with high degrees of behavioral flexibility, which greatly complexified the ensuing economic trade-off problem of how to deal with these newly gained degrees of freedom (Veit, 2023, p. 22).

The solution to this trade-off problem, Veit argues, most plausibly consisted in the emergence of an evaluative system, which utilizes valence as a common currency, that could facilitate the trade-off decisions between a wide array of available actions (Veit, 2023, p. 69). According to Veit, this is where valenced consciousness (i.e., conscious states that either feel good or bad) first came onto the scene because valenced consciousness became worth investing in because it could be utilized as a common currency by the evaluative system to deal with (high) pathological complexity (Veit, 2023, p. 70). In other words, Veit appears to believe that evidence from the lifestyle changes or organisms during the Cambrian explosion support the PCT (i.e., that it is the function of valenced consciousness to deal with high pathological complexity) independently, without relying on any evidence from the experimental paradigms that TE-theories appeal to, and without relying on other antecedent assumptions about consciousness’ function.

This way of abruptly removing the influence of insights about human consciousness does not mean that Veit cannot, or does not, rely on evidence from experimental paradigms that TE-approaches use. Quite the contrary. Some of Veit’s claims, such as the claim that valenced consciousness is the fundamental dimension of consciousness, are (partially) based on insights from humans and living animals. ⁸ However, the influence of such evidence is abruptly removed once Veit starts investigating the function and origin of valenced consciousness. This is, then, where the Copernican turn is ultimately taken: By putting front and center evolutionary considerations as an independent and credible source of evidence that can directly support hypotheses about the function and origin of minimal consciousness. This, arguably, is the defining feature of the BE-approach (de Weerd & Dung, 2025, p. 13): On a BE-approach, our understanding of human consciousness should ultimately foundationally and primarily be informed, or anchored in, an understanding of consciousness most humble beginnings based on evolutionary evidence as an independent source of evidence.

Evolutionary Considerations and Hypotheses About Consciousness

How convincing is all of this? Can evolutionary considerations really constitute an independent source of evidence that can directly support (i.e., make more plausible) hypotheses about consciousness, without also directly or indirectly relying on insights about consciousness in humans, and without making any controversial assumptions about consciousness’ nature? Can we really remove the influence of insights about human consciousness this abruptly? I think that the BE-approach in its current form fails to make a convincing case for this. Specifically, the underlying reasoning that Veit deploys strikes me as somewhat puzzling for reasons Leonard Dung and myself have suggested elsewhere (de Weerd & Dung, 2025). In what follows, I will focus on one of these reasons specifically, the one that I find most problematic for the BE-approach, and expand on it in more detail.

Suppose that we grant that valenced consciousness is indeed the consciousness’ fundamental dimension and that it was the first kind of consciousness that emerged. Suppose we also grant that it is a function of valence to play the role of a common currency. However, in that case, why are Veit’s evolutionary considerations supposed to be making a case for the need of conscious valenced processing specifically? Why does this evidence not equally well support the alternative hypothesis that there was a need for non-conscious valenced processing?

Put differently, Veit’s evolutionary considerations seem to be making a case for the need of valence simpliciter, ⁹ and the need for an evaluative system that utilizes it, to deal with the increase in pathological complexity during the Cambrian explosion, without saying anything about whether the processing of valenced states needed to be done consciously or non-consciously. This point is further bolstered by the idea that our theoretical understanding (i.e., our best theories of valence entail there are non-conscious valenced states), and empirical understanding (i.e., various experiments support the idea of non-conscious valenced processing), of valence suggests that valenced states can plausibly be processed non-consciously (see Fischer & Barrett, 2025 for a discussion on this).

But how can Veit adjudicate between these possibilities based on the evidence derived from assessing the life-history strategies of Cambrian organisms, and without resorting back to relying on TE-evidence? It is hard to see how he can in principle. What the BE-approach seems to lack, and where the TE-approach clearly seems to have an edge, is the tools to disentangle conscious from non-conscious processing directly without making too many controversial assumptions about consciousness. For instance, the aforementioned experimental paradigms that TE-proponents use to directly disentangle conscious from unconscious processing rely on fairly modest assumptions, such that consciousness (in humans) contributes to verbal reports or that consciousness facilitates some cluster of cognitive abilities (Birch, 2022). ¹⁰ On a TE-approach, these fairly innocent assumptions are enough to get the disentangling project off the ground.

But none of this is available to Veit, at least if he wants to maintain the claim that evolutionary considerations independently support the PCT. To illustrate this further, at some point Veit concedes that non-conscious means could be levied to deal with (high) pathological complexity (Veit, 2023, p. 176; see also Veit, 2023, p. 204). However, Veit argues, at the very least the Cambrian explosion reveals that valenced consciousness became “worth having” (i.e., gains sufficient adaptive value). The reasoning is, according to Veit, that dealing with pathological complexity using an evaluative system that specifically utilizes conscious valenced states, not non-conscious valenced states, is more efficient, and likely easier to achieve than the various non-conscious alternatives (Veit, 2023b, p. 205).

This reply seems problematic. First, the claim that valenced consciousness becomes worth having when an evaluative system emerged during the Cambrian explosion to deal with pathological complexity already assumes that it is, or can be, a function of valenced consciousness to deal with pathological complexity. But to assume this is to simply presuppose that the PCT is correct (de Weerd & Dung, 2025, p. 11).

Moreover, the evidence that Veit appeals to does not show why conscious valenced processing should be more efficient, have additional benefits, or is easier to achieve, when compared to non-conscious valenced processing, or any other non-conscious alternative (de Weerd & Dung, 2025, p. 11). Arguably, such claims need to be vindicated by the kind of experimental paradigms that TE-proponents appeal to, which seem much better suited to address these questions. Accordingly, it is very puzzling how the “worth having” suggestion is supposed to support the PCT. Having said that, if Veit is instead claiming that valence simpliciter becomes worth having during the Cambrian explosion, then his reasoning seems much more reasonable (see next Section).

If all of this is correct, then Veit, and more broadly the BE-approach, simply lacks the tools to adjudicate between hypotheses about conscious and non-conscious processing. That is, the evolutionary considerations Veit appeals to may give reason to think that there was a need for an evaluative system that utilized valence simpliciter, but leaves questions about consciousness’ involvement untouched. In other words, evolutionary considerations provide no independent credible source of evidence that can directly support claims about the function (or origin) of (minimal) consciousness.

Even if the PCT cannot be directly supported by evolutionary considerations, what about Veit’s suggestions that the PCT makes various empirical predictions that can be tested by investigating living animals? Specifically, Veit suggests that the PCT can be tested by evidence from living animals which (1) face high pathological complexity but (2) only have very simple evaluative, yet complex and conscious sensory, capacities: Call these animals “sensory-specialists” (de Weerd & Dung, 2025, p. 12). ¹¹ Veit suggests that if sensory-specialists exist, they constitute direct evidence against the PCT, because according to Veit the PCT suggests that valenced conscious states, which are utilized by an evaluative system, allow an animal to deal with high pathological complexity, not that sensory consciousness could have emerged by itself to deal with high pathological complexity. ¹²

But again, the underlying reasoning here is puzzling. When we come across beings that have complex sensory capacities, and simple evaluative capacities, it may simply be the case that they have non-conscious complex sensory capacities, and non-conscious simple evaluative capacities. Such a being would be a non-conscious sensory-specialist and the evidence about the complexity of their capacities—without making any antecedent assumptions about how the complexity of the capacities are linked to consciousness and without simply assuming that they are conscious—is compatible with this possibility.

However, the existence of non-conscious sensory-specialists is compatible with the PCT being true. It can both be true that (1) it is the function of (valenced) consciousness to deal with high pathological complexity and (2) that some animals found a way to deal with high pathological complexity via non-conscious means, for instance by using complex but non-conscious sensory capacities. Nothing in this scenario would indicate that it is not the function of consciousness to deal with high pathological complexity, as the PCT dictates. In fact, if the PCT is really supported (i.e., made plausible) by the evolutionary considerations discussed earlier, then wouldn’t the PCT not simply predict that if we find animals with complex sensory capacities, but simple evaluative capacities, that they lack consciousness? In other words, it is puzzling how the evidence for sensory-specialists simpliciter (i.e., without presupposing that they are conscious) could count as evidence against the PCT. ¹³

A similar argument holds for Veit’s suggestion that the existence of evaluation-specialists would count in favor of the PCT. Evaluation-specialists are organisms with complex evaluative, but only simple sensory capacities. ¹⁴ Again, absent any antecedent assumptions about consciousness’ nature or simply assuming that they are conscious, evaluation-specialists may be non-conscious creatures. For instance, evaluation-specialists might have complex but non-conscious evaluative capacities. They could even have the kind of evaluative system Veit has in mind that only utilizes non-conscious valenced states. Moreover, evaluation-specialists might in addition have simple non-conscious sensory capacities. But in that case, the existence of non-conscious evaluation-specialists would not constitute evidence that confirms the PCT, because it can both (1) be true that non-conscious evaluation-specialists exist and that (2) the actual function of consciousness is grounded in some complex sensory capacity. In other words, the existence of either sensory-specialists or evaluation-specialists simpliciter, without simply assuming that they must be conscious, would not constitute clear evidence against or in favor of the PCT, respectively.

Let’s take stock. What I have tried to show is that using evolutionary considerations, and in particular assessing the life-history strategies of organisms during the Cambrian explosion, as an independent source of evidence to motivate or support hypotheses about consciousness is ultimately problematic. ¹⁵ I have also tried to show that it is puzzling how the evidence Veit appeals to from living animals, or specifically assessing potential phylogenetic splits between sensory and evaluative capacities (Godfrey-Smith, 2020b), is supposed to directly speak in favor or against the PCT. If all of these considerations are on the right track, then Veit specifically, but also the BE-approach more generally, fails to live up to its ambitions to provide credible evidence which is (1) independent from (direct or indirect) insights about human consciousness and not are derived from the TE-paradigm discussed earlier, but which (2) directly motivates or supports hypotheses about the function (and origin) of consciousness. ¹⁶

Evaluative Modes of Being Simpliciter: A Different Way of Understanding the Pathological Thesis

Does all of this suggest that the PCT is wrong? Not necessarily. Even if the previous considerations are on the right track, Veit could still suggest that the PCT can be vindicated by experimental paradigms of the TE-approach that are equipped to directly disentangle conscious from unconscious processing. ¹⁷ Moreover, none of the reasoning that Veit is engaged in is necessarily problematic in the context of discovery, as a way of generating hypotheses about consciousness, but not justifying them (de Weerd & Dung, 2025, p. 12). However, if Veit has to retreat to the TE-approach to vindicate his hypotheses and concede that he is primarily generating speculative, but legitimate, hypotheses about consciousness without justifying them, that will clearly take the sting out of the ambitions of the BE-approach: It would undercut the need to take a Copernican turn which involves placing evolutionary considerations front and center as an independent source of evidence to justify hypotheses about (minimal) consciousness.

Having said all that, I think there is more to what Veit is doing than only generating a speculative, but legitimate, hypothesis about consciousness that ultimately needs to be vindicated by the TE-approach. That is, I cannot escape the impression that Veit’s considerations are contributing to supporting a hypothesis in the vicinity of the PCT that is valuable and important in its own right, even if it’s not revealing anything about consciousness directly. ¹⁸ Specifically, perhaps the PCT is better understood not as a hypothesis about the function of consciousness, but as a hypothesis about the utility, and perhaps inescapability, of an evaluative mode of being simpliciter that is in general worth having when faced with high pathological complexity. Call this hypothesis the:

PCT*: Dealing with high pathological complexity in general requires an evaluative mode of being simpliciter (i.e., not implicating anything about how consciousness is involved).

I think that the puzzlement of the last section is readily taken care of if we consider the evidence Veit appeals to in light of the PCT*, not the PCT. That is, it suddenly seems much more intelligible how evidence from assessing the life-history strategies of organisms during the Cambrian explosion, as well as (potential) evidence of sensory-specialists or evaluation-specialists, is justifying—or testing—the PCT*, and not the PCT. Let’s examine this in more detail.

First, as discussed earlier, the criticism that targeted the effectiveness of investigating the life-history strategies of organisms during the Cambrian explosion only suggested that it is not clear how such evidence could point to consciousness being involved. But that is consistent with saying that such evidence supports the idea that there is a rationale for postulating an evaluative system, which utilizes valence simpliciter as a common currency, that could facilitate the trade-off decisions between a wide array of available actions. In other words, there is a more straightforward link between this evidence and the PCT*.

Second, consider Veit’s remarks that the lifestyle changes of organisms during the Cambrian explosion may not rule out that non-conscious means could have been levied to deal with the increase of pathological complexity, but that it reveals that (1) valenced consciousness becomes worth having and that (2) there is an efficiency rationale to this: Achieving an organization that utilizes valenced consciousness is more efficient and easier to achieve than its alternatives. As discussed earlier, the reasoning here is puzzling. But if we substitute valenced consciousness for evaluative mode of being simpliciter then this reasoning seems more convincing.

Specifically, one could reason as follows. Even though we cannot rule out that organisms during the Cambrian explosion found a way of dealing with pathological complexity that does not involve an evaluative mode of being simpliciter, there may be good reasons to think that an evaluative mode of being is more efficient and easier to achieve than investing in a non-evaluative mode of being. Perhaps this requires some further arguments to see why this is the case, but there does not seem to be any principled problems here of adjudicating this in an evolutionary context. But none of this requires discussing how consciousness is involved.

Third, Veit (2023, p. 81) also discusses the Avalon explosion, which saw a similar explosion of pathological complexity in the Ediacaran morphospace. Veit discussed a puzzle: Why did animals with “bilaterian bodies and more discernible actions” largely disappear during this period despite the significant increase of pathological complexity? Put differently, why did the lifestyle of animals which invested more on the sensory-motor side ultimately fail? Veit suggests the following:

“While it is unlikely that this Ediacaran extinction only had a single cause, the pathological complexity thesis offers us an elegant though admittedly speculative explanation for why one explosion eventually failed, whereas the other succeeded. The answer is the necessity of an evaluating system, which enables the efficient deployment of the increase in behavioural complexity through the gradual increase in sensory-motor capacities. Whereas organisms in the White Sea failed to deal with the computational explosion of pathological complexity caused by the rapid expansion of their degrees of freedom and were thus confined to more stationary plant-like ways of life, the Cambrian saw the evolution of Benthamite creatures with hedonic valence serving as an impulse for efficient action selection at the level of the organism” (Veit, 2023, p. 82).

“The reason that I suspect the Avalon explosion “failed” is because these organisms did not come up with a design solution to pay off for this complex investment into behavioural flexibility” (Veit, 2023, p. 82).

Again, all of this straightforwardly speaks to the PCT*, not the PCT. Specifically, the PCT* suggests that an evaluative mode of being simpliciter is in general required to deal with pathological complexity. And this explains why organisms which did not invest in such an evaluative mode of being ultimately failed. Indeed, as Veit puts it: “The answer is the necessity of an evaluating system, which enables the efficient deployment of the increase in behavioral complexity through the gradual increase in sensory-motor capacities” (Veit, 2023, p. 82, italics added). This is interesting in its own right, and speaks directly to the PCT*. But none of this speaks to consciousness’ involvement, nor does it have to in order to be interesting in its own right.

Fourth, consider the possible existence of sensory-specialists again. Suppose that it was true that, for instance, bees only have very simple evaluative capacities but very complex sensory capacities leaving aside any considerations about how consciousness is related to these capacities and their complexity. This would constitute clear evidence against the implication of the PCT* that having an evaluative mode of being is universally preferable to deal with high pathological complexity. Specifically, it would suggest that there are at least some contexts in which animals may be better off in dealing with high pathological complexity by heavily investing on the sensory side, rather than investing or expanding upon an evaluative mode of being simpliciter.

Fifth, similar reasoning can be applied when assessing the evidence from evaluation-specialists. If beings exist (or existed) which face high pathological complexity have complex evaluative capacities but only simple sensory capacities, this would count in favor of the PCT*, because it would show that complex sensory capacities are not required in general to deal with high pathological complexity, further strengthening the claim that an evaluative mode of being simpliciter is at the core responsible for dealing with high pathological complexity.

Sixth, consider also how evidence of sensory-specialists in light of a reinterpretation of Veit’s claim that:

“Sensory experience is simply an outcome of an increase in evaluative complexity that allows for more stimuli to be distinguished, assigned value, and compared to enable efficient action selection” (Veit, 2022, p. 293).

If we set aside any implications about consciousness, we can reinterpret Veit’s claim as describing an implication of the PCT*:

Sensory complexity is simply an outcome of an increase of complexity of the evaluative mode of being simpliciter “that allows for more stimuli to be distinguished, assigned value, and compared to enable efficient action selection.

In other words, the PCT* predicts that further sophistication on the sensory side is a consequence of complexification on the evaluative side, and that complex sensory capacities are entangled with, and further enrich, an evaluative mode of being that lies at the core of animals that face high pathological complexity. It seems more straightforward how the existence of sensory-specialists would undermine that claim, and this does not require making any claims about consciousness. Specifically, sensory-specialists would show that complexification of sensory capacities need not only be a consequence of enriching an already existing evaluative mode of being. Instead, sensory-specialists would reveal that complex sensory capacities could come about in their own right, without requiring a pre-existing evaluative mode of being.

Seventh, Veit suggests that:

“No robot has of yet been created that would be able to handle the pathological complexity of the life histories exhibited in even the most basic of the distinctively animal lifestyles. Their failure is akin to the very same challenge [that pre-Cambrian] animal agents failed to overcome” (Veit, 2023, p. 86).

Both the PCT and the PCT* can explain this failure. It may be that robots need to be infused with valenced conscious experiences to be able to handle the pathological complexity of even the most basic animal lifestyles. But, again, given that the PCT—if the considerations given earlier—is on somewhat shaky grounds, it seems more promising to suggest, as the PCT* does, that robots have hitherto failed to handle the aforementioned pathological complexity because they lack an evaluative mode of being simpliciter. The suggestion that robots may need to be infused with an evaluative mode of being does not need to mention anything about consciousness, but is nevertheless interesting in its own right.

Taken together, I think that all of this suggests that the evidence Veit discusses is perhaps much better viewed as supporting or testing the PCT*, not the PCT. And the PCT* is a valuable and interesting hypothesis in its own right about animal lifestyles in general without having to make any claims about consciousness directly. Accordingly, I will provisionally suggest to Veit that reorienting from the PCT to the PCT* will be valuable in ensuring that Veit’s contributions have the greatest possible impact.

Conclusion

Let’s take stock for one last time. My aim here was two-fold. First, I suggested that there are various reasons to think that using evolutionary considerations as an independent source of evidence to directly support hypotheses about consciousness is ultimately problematic and unconvincing. Thereafter, I suggested that there is a different way of understanding the PCT that does not imply anything about consciousness, but which is interesting in its own right and makes it much less puzzling how the evidence Veit considers speaks to it. Accordingly, I ultimately have to conclude that consciousness science should not be turned upside down, and that Veit’s central hypotheses are perhaps better understood as hypotheses not directly concerned with consciousness.