Introduction
The philosophy of colour has long puzzled thinkers, particularly in debates over whether colours are objective properties of physical objects or subjective features of human perception. In this essay, I explore this question by engaging with C.L. Hardin’s argument against colour objectivism, as presented in his work Color for Philosophers: Unweaving the Rainbow (Hardin, 1988). Hardin contends that colour properties cannot be identical to physical properties like surface reflectances, even though these physical traits cause our colour experiences. Drawing on the provided quote, I will explain Hardin’s reasoning, focusing on his claim that nothing in the objective world adequately models the essential characteristics of colours, such as unique hues and complementary opponence. I argue that Hardin’s reasoning is logically valid, as it follows coherently from his premises, but its soundness is debatable due to potential oversights in empirical evidence about colour perception. Ultimately, I agree that a tomato’s redness is not identical to its skin’s physical properties, as this view aligns with the relational nature of colour. This analysis draws on philosophical discussions in the puzzles and paradoxes of perception, aiming to develop my thinking as a student in this area. The essay is structured to first explain Hardin’s argument, then assess its validity and soundness, and finally offer my agreement with an example.
Hardin’s Reasoning Explained
Hardin’s central argument challenges colour objectivism, the view that colours are intrinsic physical properties of objects, independent of perceivers. Instead, he advocates for a subjectivist or relational account, where colours emerge from interactions between objects, light, and human visual systems. In the quoted passage, Hardin asserts: “Apart from their radiative result, there is nothing that blue things have in common, and we have already seen that there is nothing in the structure of that radiation which could serve as counterparts to the unique hues or the opponence of complementary hues. I conclude that objectivism fails. It fails because nothing in the domain of objects, properties and processes beyond our skins is both causally connected with our colour experiences and models the essential characteristics of colours” (Hardin, 1988, p. 112).
To unpack this, Hardin begins by noting that objects we perceive as the same colour, such as various blue items, share no common physical property beyond their “radiative result”—that is, the way their surfaces reflect light wavelengths. However, he argues that even this reflectance does not capture the “essential characteristics” of colours. For instance, unique hues like pure red, blue, yellow, and green are fundamental to our colour experience, yet they lack direct counterparts in the physical spectrum of light. Indeed, the visible spectrum is a continuum of wavelengths, without discrete boundaries for these hues (Byrne and Hilbert, 1997). Furthermore, Hardin points to the “opponence of complementary hues,” a phenomenon where colours like red and green oppose each other perceptually—you cannot see a reddish-green, for example. This opponence is rooted in the human visual system’s opponent-process theory, proposed by Hering (1964), where neural channels process colours in antagonistic pairs (red-green, blue-yellow, black-white).
Hardin’s reasoning hinges on a mismatch: while physical properties like surface reflectances cause colour experiences (e.g., a tomato’s skin reflects more long-wavelength light, appearing red under normal conditions), they do not “model” the structural features of colour phenomenology. Nothing objective corresponds to the binary oppositions or unique hues that define our colour space. Therefore, objectivism fails because it cannot identify a physical property that both causes and structurally mirrors colour experiences. This argument is informed by empirical findings from colour science, which show that colour perception varies with context, lighting, and individual differences, further undermining a purely objective view (Thompson, 1995). As a student grappling with these puzzles, I find Hardin’s integration of philosophy and science compelling, though it raises questions about where exactly colours reside.
Assessing the Validity of Hardin’s Reasoning
Validity in philosophical arguments refers to whether the conclusion logically follows from the premises, assuming those premises are true. Hardin’s reasoning appears valid in this sense. His argument can be reconstructed as follows: (1) For colour to be a physical property of objects, there must be some objective feature (e.g., surface reflectance) that is both causally responsible for colour experiences and structurally isomorphic to the essential characteristics of colours, such as unique hues and opponent relations. (2) Surface reflectances and radiation patterns cause colour experiences but lack counterparts to these essential characteristics. (3) Therefore, no such objective feature exists, and objectivism fails.
This structure is deductive and logically sound; if premises (1) and (2) hold, the conclusion necessarily follows. Hardin supports premise (2) with evidence from colour science, noting that the electromagnetic spectrum is continuous, without inherent oppositions, whereas human colour vision imposes categorical structures (Hardin, 1988). Critics might argue that the requirement for structural isomorphism is too stringent—perhaps causation alone suffices for identity—but Hardin anticipates this by emphasising that mere causation does not capture colour’s qualitative essence. For example, metameric colours (different reflectances appearing identical under certain lights) demonstrate that physical properties do not uniquely determine colour experiences (Byrne and Hilbert, 1997). Thus, the argument avoids obvious fallacies, such as equivocation on “property.” However, validity does not guarantee truth, which leads to questions of soundness.
Evaluating the Soundness of Hardin’s Argument
Soundness requires not only validity but also true premises. Here, Hardin’s argument is arguably sound, though with limitations that reflect ongoing debates in philosophy of perception. Premise (1) seems reasonable, as identity theories typically demand that the identifying property accounts for all relevant features; otherwise, colours would be reduced without remainder, which Hardin shows is problematic. Premise (2) draws on verified scientific data: opponent-process theory is well-established, with neural evidence from studies on visual cortex processing (De Valois and De Valois, 1988). Unique hues also have psychological reality, as demonstrated in cross-cultural studies where speakers consistently identify them despite linguistic differences (Regier and Kay, 2009).
Nevertheless, the argument’s soundness is not unassailable. Some philosophers, like dispositionalists, argue that colours are dispositions of objects to produce certain experiences in normal perceivers, thus bridging the physical and phenomenal without requiring strict isomorphism (Johnston, 1992). Hardin might counter that this still locates colours “beyond our skins” inadequately, but it challenges his conclusion by redefining objectivism. Additionally, empirical limitations exist; for instance, advances in colour science since Hardin’s writing, such as models integrating reflectance with perceptual adaptation, might offer better mappings (Maloney, 1999). As a student, I see this as a limitation: Hardin’s reliance on 1980s science may overlook newer evidence, making his argument sound within its context but potentially less so today. Overall, while valid and largely sound, the reasoning invites critical evaluation, showing philosophy’s interplay with evolving science.
Personal Agreement and the Example of the Tomato
I agree with Hardin that a tomato’s property of being red is not identical with any property of its skin or surface reflectances. The tomato appears red because its skin reflects wavelengths around 650 nm more than others, but this physical fact does not equate to redness itself. For example, under sodium lighting, the tomato might look greyish, revealing that redness depends on the perceiver’s visual system and conditions (Thompson, 1995). This supports Hardin’s view: the reflectance causes the experience but does not model opponence or uniqueness—red opposes green in perception, yet no such opposition exists in the tomato’s physical structure. Arguably, this makes colour relational, not purely objective. However, I hesitate fully, as ecological approaches suggest colours signal environmental affordances, tying them loosely to objects (Gibson, 1979). Still, Hardin’s argument convinces me that strict identity fails, resolving the paradox of colour’s apparent objectivity versus subjective variability.
Conclusion
In summary, Hardin’s argument effectively demonstrates that colour objectivism fails because no physical property both causes and structurally mirrors colour experiences, as evidenced by the lack of counterparts to unique hues and opponent relations. His reasoning is valid, following logically from its premises, and sound insofar as it aligns with established colour science, though it faces challenges from alternative theories and updated empirics. I agree with his conclusion, particularly in examples like the tomato, where redness transcends mere reflectance. This engagement highlights the puzzles of perception: colours straddle the objective and subjective, urging further interdisciplinary exploration. Implications include rethinking realism in philosophy, potentially influencing fields like aesthetics and cognitive science. As a student, this deepens my appreciation for how paradoxes reveal the limits of our understanding.
References
- Byrne, A. and Hilbert, D.R. (1997) Readings in Philosophy and Cognitive Science. MIT Press.
- De Valois, R.L. and De Valois, K.K. (1988) Spatial Vision. Oxford University Press.
- Gibson, J.J. (1979) The Ecological Approach to Visual Perception. Houghton Mifflin.
- Hardin, C.L. (1988) Color for Philosophers: Unweaving the Rainbow. Hackett Publishing.
- Hering, E. (1964) Outlines of a Theory of the Light Sense. Harvard University Press. (Original work published 1878)
- Johnston, M. (1992) ‘How to Speak of the Colors’, Philosophical Studies, 68(3), pp. 221-263.
- Maloney, L.T. (1999) ‘Physics-Based Approaches to Modeling Surface Color Perception’, in Color Vision: From Genes to Perception. Cambridge University Press.
- Regier, T. and Kay, P. (2009) ‘Language, Thought, and Color: Whorf Was Half Right’, Trends in Cognitive Sciences, 13(10), pp. 439-446.
- Thompson, E. (1995) Colour Vision: A Study in Cognitive Science and the Philosophy of Perception. Routledge.
