How often do we meditate on the sacred stuff of existence: precious, stubborn life? Damon Young asks, do we look to nature as a blueprint for life?

We find the Roman statesman and scholar, Marcus Tullius Cicero, stylus in hand on a late May afternoon: ageing, a little bored, and achingly aware of his own weakness.

Robbed of his legal and senatorial potency by Caesar (nicknamed 'the All-Powerful' by Cicero), he withdrew to his estates, and tried to keep busy. Like his earlier exile to Greece, the lawyer bent his wiry body to books: to philosophy, moral, political and metaphysical. He formed new friendships in this spirit, amongst them the illustrious, encyclopaedic Marcus Terentius Varro.

'Like the learned men of old,' he wrote to Varro, 'we must serve the state in our libraries, if we cannot in Senate House and Forums, and pursue our researches into custom and law.'

Cicero was trying to meet with Varro in person, rather than on paper. Both had various estates around Italy, and both were wealthy enough to put on a good meal, bath and rub-down. But to no avail. The weeks went by and still no friendly conversation, no lunch, no walk by the orchards. Should Varro come to Cicero, or vice versa? It didn't matter, wrote the statesman.

'If you have a garden in your library,' wrote Cicero to his new friend, 'we will want for nothing.'

This might read strangely to modern eyes, used to sterile, air-conditioned libraries, with strict humidity controls and rules about whispering. But in Republican Rome, libraries were ordinary buildings, rarely specialised or purpose-built. A bibliotheca may simply have been plain stone and wood rooms, in one wing of a building, stacked with papyrus rolls or even wax tablets.

And in the middle of these buildings, surrounded by their collonades: a roofless square, often with Greek sculptures and temples. This was where the hortus, the garden, was planted and enjoyed. Common Romans, the plebeians, might only have had a small courtyard, or paved square with pots. Many grew basic foods, as a thin bulwark against starvation. The rich enjoyed much larger, more fertile and refined gardens, often closer to parks than yards. They were stacked with bees, fish, game birds and statuary. Cicero's correspondent, Varro, was not only well-off, but also a scholar of gardening and farming - one of his few extant works is De Re Rustica - On Farming. In light of this, it's likely that Varro did offer Cicero a well-stocked library, and in it a luxurious garden.

But why? Of all the bounties he might have asked for - silken sheets, scented oils, fine meats not outlawed by Caesar's sumptuary laws - why did the great Cicero name the garden?

Most obviously, the garden was a boon for Cicero as he aged. As he argued in On Old Age - in the voice of Cato the Elder, also a revered authority on agriculture - a disciplined, patient, studious man will retain his vivacity in his winter years.

'For where… can a man,' asked Cato, 'in that last stage of life more easily find the comforts in winter of a warm sun or a good fire? Or the benefits in summer of cooling shades and refreshing streams?'

The garden was, in other words, good for Cicero's old bones.

In Varro's hortus, and in his own, Cicero was also recreating and commemorating the ancient Greeks, and their gymnasiums: a characteristic combination of sportsground, park and school.

'Being driven from my dominion in the forum,' he wrote, 'I have erected a sort of Academy in my own house.'

The first Academy was Plato's in Athens, in a sacred grove dedicated to an ancient hero, Akademos.

But for Cicero, the allure of the garden was more profound than this commemoration. It also exemplified his philosophy. In On Old Age, Cicero demonstrated this with a humble vineyard. Cato recognised the vines' usefulness in the grapes: its contribution to health, economy and conviviality. Yet what the old man really relished was life itself: the endless business of nature.

'I am principally delighted,' said Cicero's Cato, 'with observing the power, and tracing the process, of Nature in these her vegetable productions.'

In a passage of clearly delighted detail, Cicero had Cato describe the unfurling tendrils of the grape vine; he savoured its rise, budding and shaded fruiting. This was Cicero meditating on the sacred stuff of existence: precious, stubborn life, what the Romans called natura.

As something of a Stoic, nature was at the heart of the statesman's philosophy. Nature was vital to this theory of the cosmos, and everyday life. In the nuanced work of earlier Greek scholars, nature was simply one category: the vital force in vegetative life. But for men like Cicero, it was also a catch-all word for everything rational, noble and good in the world: a euphemism for the cosmos as a unified, rational whole.

The Stoic ideal was to recognise this godly reason, and not buck or strain against it. In other words, the good man looked to nature as his blueprint for life.

'I follow nature as my surest guide,' wrote Cicero in On Old Age, 'and resign myself with an implicit obedience to her sacred ordinances.'

It worked like this: the Stoic sage knew the world was indifferent to him. He knew better than to have faith in Romantic individualism, swimming against Fate's rush. The cosmos would go on, with or without him; it would ignore his desires and fears. All this, said the Stoic, was perfectly natural: the logic of the world, its ongoing, eternal creation and destruction. All was fated - and if not predetermined, then certainly fickle and unstoppable. Knowing this, the wise man confronted life with the use of his natural gift: reason. The cosmos was managed by a divine logic, and man was given rationally to see it. By being aware of nature's rules and virtues, the sage trained his psyche; he redirected emotions, educated perceptions, stifled thoughts. In doing so, he attained that curious happiness of the ascetic: a kind of high-minded anaesthesia, without the petty highs and lows of the common man.

This is the lesson Cicero found in nature: a physical and psychological principle, which offered a weak, quiet smile as the reward for obedience. And he saw this cosmic mind at work in fields, hillsides and gardens: in tendrils and sweet grapes; in the plants' necessity, order and cycles of birth and decay.

Importantly, this was not simply a cognitive recognition: perceiving nature, and then coolly classing it as divine, or exemplary. Like many pagans - Stoic or otherwise - Cicero saw nature, its plants and animals, as beautiful and divine.

His god was not a master craftsman, assembling grapes from bits of matter. And he had no truck with the ancient pantheon, its strange parliamentary cabinet of portfolios. These were allegories, Cicero argued in On the Nature of the Gods - only fools, commoners and Epicureans took them seriously. In reality, the cosmos was permeated with divinity; each reddening leaf, drop of sticky sap and fermenting grape was suffused with mind. Alongside the astonishing perfection of the human mind and body, Cicero's Stoic, Balbus, gave a passionate portrait of the landscape, and its vegetation. He marvelled at the foresight of fruits, vegetables, seeds, all made 'for the sake of gods and men'. He praised the rhythm and regularity of life, and the providence of its design - the work of 'an intelligent being', whose genius was at work in each and every plant, including the favourite of Cicero's Cato.

'The vines cling to their props with the tendrils as with hands,' wrote the statesman, 'and thus raise themselves erect like animals.'

From Cicero himself to the villa vines he adored, was the same perfection of form and function; the same cosmic blueprint. And above it all, the bright blue sky - so often overlooked by pedantic babblers, but for the simple, patient Stoic a cause for awe, reverence.

Importantly, Cicero was not naively seduced by all this - he also gave a cutting, brutal Academy critique of Stoic theology, mocking their clumsy logic, impossible, innumerable deities, and Pollyanna idea of providence.

'When I reflect upon the utterances of the Stoics,' said Cicero's Academy man, Cotta, 'I cannot despise the stupidity of the vulgar and ignorant.'

Nonetheless, Cicero's sympathies, in this at least, were with the Stoics, as breathless descriptions of 'flowers and grass and trees and corn' suggest. If he had no truck with deified abstractions and the crowded fancy of Olympus, he had a genuine feeling for the mind at the heart of things; for the external fire of nature. Even after his even-handed exposition, he was unshaken. He believed that the Stoic cosmology 'approximated more nearly to a semblance of truth.' A guarded confession, but a confession nonetheless: Cicero's nature had a divinity in it, which no clever analysis shook off.

In Varro's villa garden, and his own at Tusculum, Cicero confronted this god. Not in the wilderness, but in a new nature: forged from human intelligence and the unfurling stuff of plant and animal life. It spoke of the Stoic god's perfect, providential divinity, but in a new language, comprehensible to mortals requiring agriculture, leisure, creature comforts.

'By means of our hands we struggle to create,' wrote Cicero, 'a second world within the world of nature.'

The garden was the statesman's second, sacred world. Nature gave man the 'power and process' of life, and then gave him reason to master it - Varro's garden library brought both gifts together.

Damon Young is an Australian philosopher and writer. His new book Philosophy in the Garden (MUP) is out now. View his full profile here.