In completing my book on the history of moral thought I had to cut the original manuscript quite considerably. Much of what has been lost is better off left on the cutting room floor. There are, however, some sections coherent enough to be worth reading. So,  I am running an occasional series publishing some of the more cogent ‘lost pages’ from the book. Previous excerpts were on Machiavelli and on Descartes. This extract is on Democritus, Thucydides and Protagoras. The book itself, which is called The Quest for a Moral Compass, will be published early next year.

He was ‘the laughing philosopher’ because, wrote Hippolytus, ‘he regarded all human affairs as ridiculous’. Democritus (c460-c370 BCE) was the last of the Presocratics (though many don’t regard him as one), and the most influential.  He was born into a wealthy family – so wealthy, it was said, that the Persian king Xerxes paid a visit as his army marched through Democritus’ home town of Abdera in Thrace during his futile attempt to conquer Greece.   Democritus spent much of his inherited wealth on travel, satisfying his thirst for knowledge, journeying to Egypt, Ethiopia and as far afield as India. He himself declared that none among his contemporaries had made greater journeys, seen more countries or met more foreign scholars.

In his Lives and Opinions of Eminent Philosophers, the third century biographer Diogenes Laertius tells a story of Democritus deliberately blinding himself in order to be less disturbed in his philosophical pursuits. It is a fanciful tale – old age rather than self-mutilation most likely deprived him of his sight – but it does convey a sense of the awe with which contemporaries regarded both Democritus’ search for truth and the asceticism to which he subjected himself in this pursuit.  He was, wrote Cicero ‘as great a man as ever lived’.

Yet, Democritus also came to be the most reviled of the Presocratics. Plato found him so distasteful that he refused to discuss his philosophy and, some claim, even wanted all his works burnt. The early Christians despised him for his alleged immorality. In truth Democritus possessed highly conventional ideas about morality, placing great store in prudence, justice and contentment with one’s lot. For an individual to achieve happiness, Democritus believed, he had to moderate his passions, balance his desires and not yearn after that which is ephemeral or unobtainable. As with the individual, so with society.  Civilization was, for Democritus, a fragile vessel easily broken by immoderation and disorder. He urged the death penalty for those that threatened the stability of the city.

But as conventional, and indeed conservative, were Democritus’ ideas of the good life, his means of arriving at them were not. It was his vision of human nature, and of the nature of the universe, that was to outrage so many.  Democritus was an atomist, who held that the cosmos, and all within it, were composed of atoms (from the Greek word atomos meaning ‘indivisible’) moving within an infinite void.

Previous cosmologies and ethical systems had assumed a universe that was both meaningful and purposeful. In Homer, the gods determined both the physical nature and the moral temper of the universe. The early Presocratics, Anaximander and Heraclitus in particular, accepted that natural phenomena were bound by law and subject to cosmic justice. ‘The sun will not overstep its measures’, Heraclites wrote, ‘otherwise the Furies, ministers of justice, will find it out.’ The laws of nature were maintained by divine sanction. If order in the universe derived from, and helped establish, a form of cosmic justice, then justice in human affairs was maintained by a natural (or supernatural) order. Good and evil, reward and retribution, were woven into the fabric of the universe.

The universe of the atomists was impersonal and without purpose. For Democritus, explanations of the world that invoked purpose were meaningless. True explanations referred only to movements of atoms, which had no goals and purposes but moved simply because of their intrinsic properties and the external forces exerted upon them. There was for atomists no such thing as cosmic justice.  But what of human justice? Human beings and their minds were part of nature; they too were composed of atoms that conformed to the same laws as all other atoms. The mind, according to Democritus, is a collection of spherical atoms somewhere in the body and thought consists in the motion of these mind-atoms as they interact with each other and with other atoms. Though we often say that we act because we have chosen to do so, we are mistaken in the same way as our ‘bastard senses’ are mistaken about the physical nature of the universe. Human acts are governed not by purpose and will but by the movements and interactions of purposeless atoms.

What does morality mean in such a universe? And how did it arise?  According to Democritus, the first humans lived an ‘unruly and bestial life’ battling alone for survival in a hostile world. Fear, not intelligence, taught them to live in groups – they had to cooperate when faced with the common enemy of wild beasts: ‘Need itself was peoples’ teacher.’ Virtue was a matter of self interest.

The historian Thucydides (c460-c400BCE) extended Democritus’ idea of virtue as self interest in a way that was to reverberate down the centuries. Born in Athens, in the year that the first Peloponnesian War between Athens and Sparta broke out, Thucydides spent much of his life contemplating the nature of war and of the role of human nature in war. His History of the Peloponnesian War is often seen as the first ‘scientific history’ and the first work of political realism.

In the state of nature, Thucydides suggests, humans are faced not just with wild beasts but with each other as enemies. It is part of human nature to dominate and for the strong to prevail over the weak.  It makes sense, therefore, for humans to choose to live under a power that can keep these impulses under check. As Glaucon puts it in Plato’s Republic, ‘Those who are able to do injustice while avoiding suffering it think it expedient to make an agreement with each other neither to do nor to suffer injustice… And this is how justice came into being, and what it is: an intermediate between the best condition, of doing injustice without penalty, and the worst, of suffering injustice without being able to retaliate.’ Almost two millennia later, Thomas Hobbes, who in 1629 published a translation of History of the Peloponnesian War, developed Thucydides’ idea into the notion of the ‘social contract’.

Thucydides and the naturalists seemed to have provided a rational account of both the origins and the maintenance of morality. Moral rules were not arbitrarily defined by gods but were the rational and necessary outcome of the development of human communities. It was, however, an idea that questioned the very concept of morality. In Thucydides’ account of human nature, people were moved to outlaw theft, murder and rape by a desire not for fairness and justice but through an instinct for power and self-preservation.

Morality made sense for the weak. But not necessarily for the strong. If, in Glaucon’s words, you faced ‘suffering injustice without being able to retaliate’, moral restraint made sense. But if you were able to experience ‘the best condition of doing injustice without penalty’ why, in Thucydides’ terms, should you not be unjust?  For Thucydides it is rational to observe moral codes only insofar as it benefits me; where I can advance my power and security by violating them, it is rational to do so. Indeed, it is moral in this case to be immoral. The study of human nature seemed to suggest that the honest, moral, just person does not know what is good for him.

Democritus believed that humans could not rely on their ‘bastard senses’ to provide truths about the world, but could trust only to reason. He wanted also to make claims about the world as it really was: a world composed of atoms moving in a void, atoms whose objective qualities were those of weight, size, shape and position. But if sensory evidence is unreliable, what can we truly know of the world? As Democritus makes the senses say in a conversation with reason,  ‘Wretched mind, do you take your proofs from us and then overthrow us? Our overthrow is your downfall.’ The very argument that leads Democritus to insist on the idea of an objective world, distinct from our subjective impressions of that world, also leads him to suggest that it may be impossible ever to apprehend it.

This line of reasoning led some in the Ancient world, such as Pyrrho of Elis (c. 360-270 BCE), towards scepticism: the belief that, in the words of the second century philosopher Sextus Empiricus (c. 160-210 CE), one must ‘suspend judgment’ on the truth of any claim because it is impossible to resolve the differences among the contrary attitudes, opinions and arguments.

Many fifth century philosophers were sceptical of such scepticism. But they remained unsure about how it should be opposed. One influential answer came from Protagoras (c 490– 420 BCE). Born in Abderas in north-eastern Greece, Protagoras was a Sophist, a group of itinerant teachers and philosophers who taught literature, politics, history, physics and mathematics, but most of all who taught the ability to speak, hold an argument and convince an audience. Unlike many Sophists who were drawn to the sceptical consequences of the atomists’ philosophy, Protagoras was hostile to the notion.  His critique of Democritus involved, however, the philosophical equivalent of slash and burn.

Protagoras rejected scepticism by discarding the distinction between appearance and reality.  In so doing he was drawn to discarding naturalism in its entirely. For Democritus, if the same water appears cold to you and warm to me it is because our senses are unreliable. For Protagoras, it is because the water really is both cold and warm. Reality, and truth, is self-created and subjective, not independent and objective. ‘Man is the measure of all things’, he suggested, ‘of things which are, that they are, and of things which are not, that they are not’ adding that ‘as each thing appears to me, so it is for me, and as it appears to you, so it is for you’.

The price that Protagoras paid for navigating around scepticism was an incoherent attitude to truth. Every individual made his own truth. And within a community, truth was that of the many. In an age, and in a city, attempting to find philosophical and ethical foundations for democracy, this may have appeared an attractive argument, but it laid to waste the very idea of truth as referring to any kind of objective reality. Protagoras showed how to avoid perpetually suspending judgement but only by making judgement itself non-judgemental.

The problem of judgment became a particular issue in ethical debate. If truth is subjective, how could we choose rationally between different moral systems? If democracy appears just to Athenians, and military rule to the Spartans, are both democracy and military rule just? Athens had in recent times gone through oligarchy, tyranny and democracy. Which was better? ‘Whatever in any city is regarded as just and admirable’, Protagoras suggests, ‘is just and admirable in that city  for so long as that convention maintains itself.’ Democritus had insisted that nature trumped culture (or ‘convention’ as he put it). Protagoras believed that convention was all.

In the three centuries between Homer and Protagoras there developed three fundamentally distinct claims about morality. For Homer, morality was defined by the gods. This seemed to make it arbitrary in both its content and its execution. For Thucydides, Democritus and many Presocratics, morality was defined by nature and by human nature. It was a claim that appeared to undermine the very basis of morality. For Protagoras, morality was humanly created. But this made it impossible to know why we should prefer one moral code over another. These three moral outlooks, and moral dilemmas, thread their way through the history of moral thought.