In ‘The Emergence of the Concept in Early Greek philosophy’, André Laks argues that we can trace the first inklings of thinking about concepts by paying close attention to early Greek answers to the following three questions: how is perceptual information reached and processed by the mind, what is the relationship between perception and thinking, and how do the early Greek philosophers account for name-giving? First, Laks discusses whether the explanations of sensory mechanisms offered by the early Greek philosophers as well as by the medical authors might have prepared the ground for later theories of concept formation. Second, he argues that we should resist the Aristotelian report according to which the early Greek philosophers identified thinking with perceiving. In fact, we have good reasons to assume that early Greek philosophers attempted to offer an account of the process of thinking. The final section of the chapter turns to the question of the relationship between giving names to things, and forming and grasping the corresponding concept.

Ancient Greece provided the setting for the first detailed, recorded hypotheses about the causes of human activity. In the search for first principles of life, tentative explanations included: The naturalistic orientation of the Ionian physicists Democritus, Heraclitus, and Parmenides looked to some basic physical element in nature as this first principle. A biological orientation, developed by Alcmaeon, Hippocrates, and Empedocles, held that bodily physiology is the key. Pythagoras held that life is transcendent of the material world and found in the essential coherence of mathematical relationships. The Sophists posited a pragmatic orientation that denied the value of trying to seek out first principles, relying instead on observations of life as it is lived. Finally, Anaxagoras and Socrates, rejecting the Sophists, proposed the existence of a soul that defines humanity. This humanistic orientation developed the notion of the spiritual soul that possesses the unique human capabilities of the intellect and the will. The soul was elaborated as the central element in the interpretation of life offered by Plato and Aristotle. By the end of the Greek era the critical themes and issues of psychology as well as the methodological approaches were well identified and structured.

Why would a fourth-century BC Atomist – Anaxarchus – express his scepticism about knowing the truth of things by imaging these as scene-painting? The comparison seems already to have been made by Democritus and Anaxagoras, who according to Vitruvius had been impressed by something an Athenian painter named Agatharchus had written on perspective. This chapter offers a detailed scrutiny of a range of texts that have a bearing on the interpretation of Vitruvius’ claim. It argues that Agatharchus was probably author of a pioneering treatise on stage-building, which included a section on scene-painting lauding its power to create the illusion of a whole three-dimensional world. Anaxagoras will have taken this claim as cue for his dictum: ‘Appearances are a sight of things unseen’ – in the sense that there is no break between the macroscopic world of ordinary observation and the microscopic world which explains it. The Atomist Democritus will no doubt have imparted a quite different spin to Anaxagoras’ slogan in praising it. But it is unlikely that either Presocratic was prompted to a mathematical interest in perspective by reading Agatharchus. It is only with the Hellenistic philosophers, and especially Epicurus, that optics begins to leave its trace on general epistemology.

It is a commonplace among scholars that the early Pythagoreans posited an immortal soul. The earliest source to associate immortality of the soul to the Pythagoreans unequivocally, Dicaearchus of Messana, stipulates that they held that (a) the soul is immortal; (b) it changes into other kinds of animals; (c) there is eternal recurrence; and (d) embodied animate creatures are of the same genus. A problem with Dicaearchus' account is that each of these doctrines can also be found in the dialogues of Plato. Given Dicaearchus' penchant for conflating Platonic with Pythagorean philosophy, we cannot employ this account for a historical understanding of Pythagorean psychology in a straightforward way. This chapter instead investigates Pythagorean psychology through analysis of two passages of Aristotle’s De anima that are often not brought to bear on the question. One passage draws important comparisons between the psychology of the Pythagoreans and Democritean and Ecphantic atomism, suggesting that the early Pythagoreans held a material theory of soul; by reference to arguments similar to Cebes' in Plato's Phaedo (87b-e), the other explains how a transmigratory soul could nevertheless be mortal. The early Pythagoreans are thus likely to have held that the soul is material, mortal, and transmigratory.

This section substantiates the claim that Xenophanes, Parmenides and Empedocles played an instrumental role in the emergence of what may be termed the Classical conception of literature – that is, the view that a work of literature is a mortally crafted artefact that reflects a true state of affairs only symbolically or mimetically – by drawing attention to evidence for their influence on certain important developments in fifth- and fourth-century BCE poetics. These include (a) fifth-century practices of allegorical interpretation; (b) Gorgias’ statements that poetry is deceptive and is a kind of charm or drug; (c) Democritus’ physical explanations for poetic inspiration and composition; (d) Democritus and the sophists’ analytical approaches to language; and (e) the conceptions of mimesis presented by Plato.

This chapter turns to Karl Marx’s treatment of Epicureanism and Lucretius in his doctoral dissertation, and argues that the questions raised by Marx may be brought to bear on our own understanding of Epicurean philosophy, particularly in respect of a tension between determinism and individual self-consciousness in a universe governed by material causation. Following the contours of Marx’s dissertation, the chapter focusses on three key topics: the difference between Democritus’ and Epicurus’ methods of philosophy; the swerve of the atom; and the so-called ‘meteors’, or heavenly bodies. Marx sought to develop Hegel’s understanding of Epicurus, in particular by elevating the principle of autonomous action to a first form of self-consciousness – a consideration largely mediated by Lucretius’ theorization of the atomic swerve and his poem’s overarching framework of liberating humans from the oppression of the gods.

Betegh explores to what extent the Presocratic philosophers made the motive power of heat topical, and how they tried to provide an explanation of that power. He argues that while the motive power of heat never seems to obtain a principal role in the cosmological theories of the Presocratics, it appears to take a more important role in the explanation of living beings in a number of theories.

Deployment of the notion of kosmos has been much discussed in the scholarship on Presocratic philosophy. But diakosmos and diakosmêsis have been almost entirely neglected. This chapter argues that in describing the business of articulating ‘mortal belief’ as diakosmos, Parmenides bequeathed to his successors among the Presocratics a question – intended as deflationary – about the main agenda for physics and physical explanation: how the universe is arranged. He coined a concept designed to articulate it. Diakosmos was a concept his successors were determined to reinflate, but only at the price of contestation between believers in a single world produced by design and proponents of infinite undesigned worlds. And in Aristotle, diakosmêsis is re-invested with a hint of the deflationary.

The concept of kosmos did not play the leading role in Aristotle’s physics that it did in Pythagorean, Atomistic, Platonic, or Stoic physics. Although Aristotle greatly influenced the history of cosmology, he does not himself recognize a science of cosmology, a science taking the kosmos itself as the object of study with its own phenomena to be explained and its own principles that explain them. The term kosmos played an important role in two aspects of his predecessor’s accounts that Aristotle rejected: first, cosmogony and kosmopoiia, generation or creation of the kosmos; second, diakosmêsis, arranging of a plurality of kosmoi. Aristotle was extremely critical of accounts involving kosmopoiia and diakosmêsis and developed general dialectical strategies against them. In emphatically distinguishing his view from all his predecessors' (including Plato), he uses the terms ho ouranos (the heaven), to holon (the whole) and to pan (the totality) in preference to ho kosmos (the kosmos or world). There is usually no harm in speaking loosely of ‘Aristotle’s cosmology’ when referring to his concept of the order of nature and the ouranos. Nevertheless, Aristotle’s theoretical philosophy offers something very different from those of his predecessors, for whom kosmos was a keyword.