Our modern scientific explanation of colour as a subjective impression has replaced a ‘pre-theoretical’ notion of colour as an intrinsic property of objects, which was mainstream in ancient thought. Why have we lost such pre-theoretical notion, and what have we lost by losing it? I argue that most ancient Greek philosophers exploited this pre-theoretical assumption – one that was obvious to them – in terms and ways that are still worthy of attention in the context of contemporary philosophy of colour. (...) I offer an in-depth analysis of the theories of a number of early Greek philosophers, as well as of Plato in the Timaeus, showing that they tend to share the idea that colour is an essential property of external bodies and therefore plays a causal role in perception. Then I focus on a comparison between Democritus’ stance and Aristotle’s in order to highlight a significant contrast between the two. Democritus' theory is an exception in ancient thought because it traces the colour phenomenon back to a refraction of atmospheric light through atomic aggregates. Aristotle, instead, posits the presence of colour and light in the bodies themselves. Finally, I interpret Aristotle's account as the most complex attempt in ancient thought to weld together what we call the ‘manifest image’ of colour and its ‘scientific image’. (shrink)

In a series of recent papers, Emily Katz has argued that on Aristotle's view mathematical sciences are in an important respect no different from most natural sciences: They study sensible substances, but not qua sensible. In this paper, I argue that this is only half the story. Mathematical sciences are distinctive for Aristotle in that they study things ‘from’, ‘through’ or ‘in’ abstraction, whereas natural sciences study things ‘like the snub’. What this means, I argue, is that natural sciences must (...) study properties as they occur in the subjects from which they are originally abstracted, even where they reify these properties and treat them as subjects. The objects of mathematical sciences, on the other hand, can be studied as if they did not really occur in an underlying subject. This is because none of the properties of mathematical objects depend on their being in reality features of the subjects from which they are abstracted, such as bodies and inscriptions. Mathematical sciences are in this way able to study what are in reality non-substances as if they were substances. (shrink)

There is little agreement about Aristotle’s philosophy of geometry, partly due to the textual evidence and partly part to disagreement over what constitutes a plausible view. I keep separate the questions ‘What is Aristotle’s philosophy of geometry?’ and ‘Is Aristotle right?’, and consider the textual evidence in the context of Greek geometrical practice, and show that, for Aristotle, plane geometry is about properties of certain sensible objects—specifically, dimensional continuity—and certain properties possessed by actual and potential compass-and-straightedge drawings qua quantitative and (...) continuous. For their part, the objects of stereometry are potential sensible three-dimensional figures qua quantitative and continuous. (shrink)

Recent interpreters portray Aristotle as a Protagorean antirealist, who thinks that colors and other perceptibles do not actually exist apart from being perceived. Against this, I defend a more traditional interpretation: colors exist independently of perception, to which they are explanatorily prior, as causal powers that produce perceptions of themselves. They are not to be identified with mere dispositions to affect perceivers, or with grounds distinct from these qualities, picked out by their subjective effect on perceivers (so-called “secondary qualities”). Rather, (...) they are intrinsic qualities of objects, which are in reality just as they appear to be. At the same time, Aristotle rejects any “simple theory of color” according to which the essence and nature of colors is fully revealed in experience. Although the character of perceptibles as they are experienced is “better known to us,” their essence and nature only comes to be known through a correct theory. (shrink)

Sense experience, naïvely conceived, is a way of knowing perceptible properties: the colors, sounds, smells, flavors, and textures in our perceptual environment. So conceived, ordinary experience presents the perceiver with the essential nature of a property like Sky Blue or Middle C, such that how the property appears in experience is identical to how it essentially is. In antiquity, as today, it was controversial whether sense experience could meet the conditions for knowledge implicit in this naïve conception. Aristotle was a (...) partisan in this debate, but his position is poorly understood. This dissertation examines how Aristotle’s perceptual psychology responds to ancient challenges to the naïve conception, and so articulates his defense of perceptual knowledge. -/- Aristotle’s defense relies on an ontology of “perceptual qualities"—a core class of perceptible properties—according to which those qualities, despite having a perceiver-independent essence rooted in the physics of causation and affection, nevertheless can be present in experience as they essentially are. Chapter 1 defends this realist and objectivist reading against competing interpretations, which overlook a crucial distinction between perceptual qualities and perceptual objects. Chapter 2 presents Aristotle’s ontology as a physicalism that uncharacteristically allows for perceptual qualities to appear in experience as they essentially are. -/- This ontology informs Aristotle’s account of the psychological conditions under which perceivers actually are presented with the essence of perceptual qualities. The locus of this account is an obscure passage where Aristotle purports to show that the senses “discriminate” perceptual qualities because the senses are “mean states” (An. 2.11, 424a5–7). Chapter 3 develops a comprehensive interpretation of the sensory mean state, which Chapter 4 uses to elucidate Aristotle’s argument for sensory discrimination. Sensory discrimination turns out to be a process in which the essence of a perceptual quality comes to be present in the affection it produces in a perceiver. For Aristotle, this shows that sense perception meets a condition for knowledge that his predecessors, including Plato, thought it could not meet. For in his view, but not in theirs, sense experience shares in both the truth and the essence of the qualities it perceives. (shrink)

Now with extra footnotes, by editorial demand! Final version accepted by Oxford Studies in Ancient Philosophy. -/- This essay consists in a trick and a potential insight. The trick consists in a minimalist interpretation of color mixture. The account of color mixture is minimalist in the sense that, given certain background assumptions, there is no more to Timaeus’ account of color mixture than the list of the chromatic pathēmata and the list of how these combine to elicit perceptions of all (...) the colors. The only potential controversial elements of the minimalist interpretation are the relevant background assumptions and the interpretation of the chromatic pathēmata. The potential insight concerns a motive that Plato, in the guise of Timaeus, may have for presenting an account of color mixture. Specifically, I shall argue that on the minimalist interpretation, Plato may be read as reconciling the Democritrean four color scheme with an older tradi- tion where white and black are the fundamental chromatic opposition. As we shall see, this bears on the interpretation of the chromatic pathēmata. (shrink)