This chapter considers how, between the mid twelfth and the mid thirteenth century, the theme of free will was addressed according to two major lines of investigation: on the one hand, that of the relationship between free will and the different powers of the soul; and on the other hand, the idea that free will should be understood as a process divided into several steps.

This chapter looks at Kant’s understanding of the relationship between laws of nature and those of freedom in order to further explain Kant’s grounding argument at 4:453. The two sets of laws constitute two systems, the first governing phenomenal nature and the second the intelligible world, that is, the systematic interrelation of rational wills. How the two sets of laws relate reveal one fundamental philosophical system that can be grasped correctly only from the standpoint of practical reason, namely, that of the agent making use of its intelligence in its practical activity. It is the same understanding and the very same transcendental subject who gives the law to nature, who also gives the law to itself, using the same set of concepts, only differently applied. Our law-giving function in both worlds grounds the primacy of our membership in the intelligible world. Different criteria of application of these concepts to noumenal and phenomenal worlds are discussed, and I show how Kant avoids objections to the idea of timeless agency. Kant espouses a modified Leibizianism through which the intelligible and sensible worlds are harmonized indirectly by the author of nature, who harmonizes the functions in us through which the two are constituted.

In this chapter, I argue that a comprehensive picture of Platonic autonomy must be balanced by attention to mutual interdependence and the ways that ideas arise through interpersonal dialogue. Philosophical ideas arise in a social context, and to this degree, even ideas that are now ‘my own’ have come to be mine in part through the reasoning of other persons. Moreover, as a result of human fallibility, even the fully developed Platonic philosopher still requires conversational partners to both learn and to test out ideas. Rather than overvaluing self-sufficiency, a philosophical life includes being open to challenges to one’s ideas, tolerating a state of not knowing fully, and learning that one needs others due to the limits of individual reasoners.

This chapter analyzes the Republic’s theory of the tripartite soul regarding the question of self-rule and autonomy. Only when the soul is in the ideal position of having reason positioned as sovereign ruler can a person be seen as acting autonomously. But it is not clear that when reason rules, it also motivates actions. Christine M. Korsgaard has argued that personal decision-making should be seen as analogous to political decision-making. She conceives of political decisions as a process where requests for action spring from the people, while rulers suffice to say yes or no. This chapter claims that this analysis is inadequate as a theory of how Plato portrays the relationship between the parts of the soul and of decision-making in general, and offers an alterantive interpreation in terms of what is called the Complex Model of Decision-Making.

Vitruvius’ De architectura (c. 35–23 BCE) offers an ideal lens through which to view the emergence of the Imperial artes. In the introduction to his work, Vitruvius develops an elaborate theory of architectural knowledge that connects the discipline with other branches of specialized knowledge and gives pride of place to causal explanations of architectural method via natural first principles. Vitruvius’ theory is tailored to architecture but is of wider importance in that it establishes a general notion of ars predicated on the scientific premises sketched in Chapter 2. True to his expansive conception of the discipline, throughout his treatise Vitruvius carefully explains his methods in terms of natural first principles, demonstrating their fundamental soundness. His advice for orienting city streets and walls (Book I) and for choosing building materials (Book II) exemplifies his characteristic interest in connecting architecture with a broader understanding of nature.

Of Celsus’ Artes (early first century AD), which originally handled agriculture, medicine, the art of war, rhetoric, and philosophy, only the eight books on medicine survive. Celsus’ work attests to the vibrant interdisciplinary culture of the early Imperial artes. The books De medicina in particular reveal a distinctive conceptualization of specialized knowledge that bears the hallmarks of the scientific culture of the artes but contrasts sharply with the approaches of Vitruvius and Columella. Celsus’ theory of the medical ars self-consciously appropriates but also develops and expands key methodological terms from the Greek medical tradition, including reason, experience, cause, and nature. These terms set the parameters for Celsus’ exposition of medicine, as exemplified in discussions of bloodletting, fevers, and fractures. Celsus’ more reserved attitude toward the kind of knowledge of nature required for expertise does not ignore the central preoccupations of the scientific culture of the artes, but instead pragmatically inflects them for medical practice.

Chapter 9 illustrates the immediate counterblast to which Price’s critics were subjected by a number of writers who continued to insist that liberty is a matter of possessing an independent will, not merely of not unrestrained from acting as you choose. Some leading Anglicans took up this position in their support of Price, including Richard Watson and Peter Peckard. But it was Price himself who answered his critics most fully. He admitted (although not explicitly) that he had given too broad a definition of slavery, but forcefully denied that he had confused the state of being at liberty with that of possessing security for your liberty. He countered that, unless you are free from the possibility of being restrained, you are not in possession of your liberty, because you remain in a condition of subjection and servitude. The chapter concludes by noting that this way of thinking about liberty gained much additional support after the outbreak of the French Revolution in 1789. Burke denounced the revolution, but he was in turn denounced by Catharine Macaulay, Mary Wollstonecraft and Thomas Paine, all of whom saw in the revolution a successful uprising against arbitrary and despotic power in the name of liberty as independence.

Hegel’s Philosophy of Nature is integrated into the fabric of his system. We absorb into our thinking the concepts and relationships that have survived the successes and failures of experience (Phenomenology). Through disciplined thought we articulate the internal logic of those concepts (Logic). By working out what the world beyond thought would be like, seeing how the world instantiates those expectations, and then building those discoveries into our next ventures, we develop a systematic picture of the stages of natural complexity and human functioning (Philosophies of Nature and Spirit). Since Hegel’s time, however, we have discovered that nature has a history; time and space are no longer absolutes; the discoveries of science have expanded in both breadth and detail; and our comprehensive explanations for the way the world functions are continually being falsified by the discovery of new facts. A philosophy of nature, then, needs to reshape the way reason functions. Adopting the strategies we use to solve problems and that science uses to develop and test hypotheses, we broaden our perspective to cover multiple domains in nature and search for patterns that show how and why they fit together as they do.

This chapter argues that Hegel’s aim in his philosophy of nature is not to compete with natural science but to show that there is reason in nature – reason that science cannot see but that works through the causal processes discovered by science. It considers first the transition from Hegel’s logic to his philosophy of nature and argues that the latter continues the project of the former, starting with reason, or the “absolute idea”, as nature, as sheer externality. It then argues that Hegel derives nature’s categories logically – a priori – from the idea-as-externality, and subsequently matches them with empirical phenomena (rather than constructing categories to fit the latter). It provides an abridged account of Hegel’s physics in order to show how the categories of physical (as opposed to mechanical or organic) nature are derived from one another and how they are embodied in physical phenomena, such as sound, heat, and magnetism. It then concludes by arguing that, contrary to appearances, Hegel’s conception of light complements, and is not simply at odds with, that presented by quantum physics.

This chapter discusses the famous Plotinian image of the transparent, luminous sphere, appearing in several versions in different treatises. Psychic contemplation is divided into two levels: imaginative and dianoetic. The first corresponds with the level of Nature by virtue of our higher imagination, while the second one corresponds with the level of the World Soul by virtue of our reason. At the imaginative level, we overcome the sense that we are located in our head and experience a sort of the expansion of our self, in which we feel ourselves permeating the whole of the sensible world. At the dianoetic level, we find ourselves to be present everywhere in a completely non-localised and non-extended way. Our reason becomes the transparent sphere in which we see all the sensible world, but this doesn’t mean that we use discursive thinking or that we analyse the world. Reason is an intuitive, “transparent eyeball”, in which we see everything as united and through which we see the sensible qualities in their archetypes, the higher logoi in the World Soul. It is freedom from anything spatial, temporal, and sensible. The world is seen as existing in ourselves, but we are not the world.

The Cambridge Platonists’ philosophy of religion might be summed up as a tension between their commitment to the fixed nature of reason and goodness on the one hand and a commitment to freedom and distaste for all forms of tyranny and imposition on the other. This last chapter contends that the Cambridge Platonists not only acknowledge this tension, but embrace it, revelling in the paradoxical way that absolute fixedness and absolute freedom come together at the highest levels of being. This is made possible by what Stephen Darwall (writing specifically of Cudworth) has identified as an early theory of ‘practical reason’. This Platonic theory of practical reason draws together all the elements of the Cambridge Platonists’ outlook considered in earlier chapters – moral realism, divine communicative intent, and participatory epistemology, illustrating the extent to which this Platonic outlook binds together not only the thought of Whichcote, More, Cudworth and Smith but also runs through each of their views on different philosophical topics such as obligation, freedom and pedagogy.