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University of California, Santa Cruz
The concept of Natural Goodness is Philippa Foot’s moral appropriation of Michael Thompson’s analysis of the logical representation of life forms. Campagna and Guevara (C&G) have taken over the concept of Natural Goodness and applied it to their project of developing a new language for conservation in hopes that their application of it in this domain can help bring out what the philosophically empty notion of nature’s “intrinsic value” would otherwise communicate. They think that a new language toward this purpose will help shape our ethical thinking about conservation, and specifically they are interested in a language that can answer morally significant questions like “What is lost when a species goes extinct?” This paper reviews C&G’s project, both their motivations and the details and application of their theory thus far. I then point out that a crucial shortcoming of their work to date is that they have yet to address the issue of how we know, or how we are in touch with the value of Natural Goodness. In other words, what justifies us in claiming that the concept of Natural Goodness carries within it a moral value at all? I suggest that an Aristotelian conception of human virtue points toward affective perceptual capacities as the ground for knowledge of the moral value of Natural Goodness. I connect this to some of the insights put forth by Kant in his third Critique, arguing that the appropriate affective state for being in touch with the moral value of Natural Goodness is the feeling of disinterested pleasure. I consider some potential objections to my appropriation of Kant’s philosophy to this specific end, and I close with a Wittgensteinian word on the limits of language in communicating ethical or moral values generally.1 (more…)
Oxford Brookes University
Gardens are seen as having metaphysical and theological significance. Many think of the Garden of Eden as the first garden, and the four rivers in Eden, mentioned in both the Bible and the Quran, are represented by four watercourses in Islamic royal gardens and by four paths in the cloister gardens of Christian monasteries and churches. Japanese Zen gardens are designed to aid meditation on eternity, and so-called paradise gardens are earthly attempts to model the celestial gardens of the gods. In this volume, Robert Neuman explores how the garden of Versailles was designed as a reflection of the divine, laid out according to principles of Pythagorean and Cartesian philosophy. This rationalist tradition continues today in the Garden of Cosmic Speculation in Scotland, where the design reflects the ‘birth, laws, and development of the universe;’ the ‘garden … in part, a speculation about the underlying truths;’ the gardener involved in ‘translating the insights of science and philosophy into workable objects.’ 
The English picturesque tradition rejects such a formal approach and the laying out of gardens according to precise geometric rules. The British empiricists of the seventeenth and eighteenth centuries saw the mind as consisting of a flux of thoughts derived from experience, rather than as a collection of innate ideas planted in us by God. This empiricist focus on experience can be seen in English landscape gardens of the time. Gardens are not a reflection of divine structures, but rather, places that are designed in order to affect the flow of our sensations. The focus is on sensation and experience, rather than reason. Here, Elizabeth Rogers notes how gardens can bring about such changes:
The power of ruins to inspire a mood of elegiac melancholy, of dark-toned vegetation to turn the thoughts into paths of sombre reflection, of bright green meadows to soothe the agitated soul, of sunny fields reminiscent of harvest revels to raise the spirits to the level of gaiety, of still brooks and placid lakes to speak of peace and serenity, of loud tumbling waterfalls to induce a thrilling fear. 
Gardens, then, can be seen as reflecting the dominant philosophical theories of their time and place. In this essay, though, following various lines of thought of the Scottish philosopher David Hume (1711–79), I shall argue that gardens can be a refuge away from metaphysics and philosophical reflection and that they can therefore play a therapeutic role.
Part I: Candide
Voltaire, a contemporary of Hume, wrote Candide as a parody of religion and of religious apologies for the existence of evil in the world. That there are morally corrupt people and that the world is occasionally beset by natural disasters looks to be incompatible with a morally perfect God, one who is all-powerful and who could presumably eradicate such evils. ‘One could grumble rather at what goes on in our one [world], both physically and morally.’  Candide’s tutor, Doctor Pangloss, teacher of ‘metaphysico-theologico-cosmo-codology’ – a thinly disguised Liebniz (an Enlightenment metaphysician) – argues, however, that we live in ‘the best of all possible worlds,’ as a benevolent God would have created. His ‘theodicies’ are explanations designed to account for the existence of evil: ‘if Columbus, on an island in the Americas, had not caught this disease [syphilis] which poisons the spring of procreation … and which plainly is the opposite of what nature intended, we would have neither chocolate nor cochineal.’  The humor is pointed, since philosophers and theologians had performed various contortions to explain away the fact that the world does not seem to be the creation of a perfectly benevolent supreme being – and they continue to do so to this day. Candide has many adventures while continuing his philosophical discussions with Pangloss and others; his final optimistic note, though, is not that of his tutor, but the enigmatic claim that ‘we must cultivate our garden.’ 
This claim has been interpreted in various ways. Voltaire could merely be suggesting that the world is indeed full of evils and that it would be wise to retreat to our own little patch and make the best of it. There is, though, a deeper sense to such a ‘retreat,’ one that can be illuminated by looking at the philosophy of another great Enlightenment thinker, David Hume, with whom Voltaire was in occasional correspondence. Writing to Hume, Voltaire says: ‘The abetters of superstition [religion] clip our wings and hinder us from soaring.’  Hume claims that we should reject philosophical thinking and return to the concerns of common life – the garden, then, being a metaphor for a life free of metaphysics and theodicy. I shall also argue that gardening itself is exactly the sort of common life activity that could contribute to this therapeutic rejection of philosophy and theology.
Part II: Hume and Common Life
Hume is suspicious of metaphysics and particularly hostile towards organized religion. His Dialogues Concerning Natural Religion contain seminal criticism of various arguments for the existence of God. In his Enquiry Concerning Human Understanding he argues that there has never been any good evidence for the occurrence of a miracle and there is never likely to be any. And in his Natural History of Religion he provides a naturalistic account of religious belief, one grounded in fear rather than rational insight or evidence. One aspect of Hume’s rejection of religion takes place at the level of common life. His strategy is to remind anyone tempted by religion of their usual everyday ways of thinking. We have to remind ourselves of how we would normally think when not led astray by psychological factors associated with religious belief. In the case of miracles, for example, Hume claims that people are swayed from their usual ways of thinking by several distorting psychological factors. The thought of supernatural intervention fills us with awe, and ‘the passion of surprise and wonder, arising from miracles being an agreeable notion, gives a sensible tendency towards the belief of those events.’  Our vanity is also massaged if we can report such events: ‘But what greater temptation than to appear a missionary, a prophet, an ambassador from heaven?’  It is such factors that cause us to believe in supernatural occurrences; such factors that promote the mere idea of the occurrence of a miracle to actual belief in such a happening. Hume therefore asks us to imagine what would be believed if these factors were not present; if, say, passion and wonder did not give rise to belief, and if our fellows were not impressed with stories concerning such things. If this were so, then we should explain away such improbable events in the way that Hume describes, and this is just what we do in everyday situations. One believes that somehow a melon seed found its way into the greenhouse if melons start to grow there unplanned (as they have done this year in my greenhouse!); one does not believe that such growth is miraculous. Similarly, one should believe that one has been tricked or one has misunderstood when asked to believe that a man has risen from the dead. Hume does not criticize belief in miracles on philosophical or logical grounds; instead, he offers us reminders as to how we usually think, and how we should therefore think when we are asked to believe in miracles.
Hume’s rejection of metaphysics is not limited to religion. Philosophers have an unhealthy attraction to extreme skepticism. Plato sees the world of experience as akin to mere shadows cast on the walls of a cave, shadows of the real things in Platonic Heaven. Descartes meditates on the possibility that our experience of the world could all be a dream or hallucinations planted in our minds by an evil demon. Hume, too, at times adopts such a skeptical perspective and argues that we can only have knowledge of our own sensations; we cannot, as it were, get behind these to take a direct look at the world that we only assume is causing our experience. Further, our experience is regular in various ways: the sun comes up every day and the leaves fall every autumn. We have, however, no philosophical reason to think they will continue to do so. Why think the world (or, rather, our experience) will continue on in the same way? Hume thinks there is no satisfying philosophical answer to this question, and this is worrying: it leads to ‘philosophical melancholy and delirium.’  However, in the face of such skeptical arguments, Hume argues that we should rescind to our everyday thinking: act, as everyone in fact does, as if the sun and the seasons will continue to behave as they always have.
Hume does, however, distinguish between the kinds of reasoning we pursue in everyday or common life. There is the vulgar reasoning of the ‘peasant’ and a more sophisticated form of reasoning.
‘A peasant can give no better reason for the stopping of any clock or watch than to say, that commonly it does not go right: But an artisan easily perceives, that the same force in the spring or pendulum has always the same influence on the wheels; but fails of its usual effect, perhaps by reason of a grain of dust, which puts a stop to the whole movement.’ 
Here, the artisan has a more sophisticated grasp of induction. Regularities are sometimes disturbed because there is a ‘secret opposition of contrary causes.’  The artisan explains a broken watch in this way; a kitchen gardener similarly explains his unusually poor harvest as due to cucumber mosaic virus or spider mites. Gardening, then, is the sort of pursuit that aids this immersion in common life and in doing so it inculcates epistemic virtues; it helps us to be good everyday reasoners, developing our appreciation of the regular run of the world. It is an activity especially well suited to this since gardeners must be sensitive to regularities of varying scope – those, for example, manifest by the seasons, the weather, disease, and germination. A garden is in many ways a microcosm of the natural world: we must be aware of long-term and short-term changes and how they embed together. Gardeners are artisans par excellence, having a fine-grained appreciation of the causal structure of nature. And the gardener’s acquiescence in common life reasoning steers clear of psychologically dangerous metaphysical reasoning and, as we shall see, of the cycle of enthusiasm and melancholia characteristic of religious belief.
For Hume, religious beliefs are akin to an illness; they are disruptive to our mental life and action, and thus they should be rejected; not just for epistemic reasons (that is, because they are false), but also for reasons concerning mental health and the security of our human nature. As seen, such beliefs are not rejected by providing philosophical argument to refute them; rather, they are rejected by embracing everyday cognitive standards, by confining ourselves ‘to common life, and to such subjects as fall under daily practice and experience.’  If we are successful in this, then the ‘contagion’ of religion shall not infect us.  Hume has a ‘therapeutic’ approach to religious belief. Religion, for Hume, is an ‘infliction,’ ‘a natural frailty,’ nothing but ‘sick men’s dreams.’  ‘As superstition arises … it seizes … the mind, and is often able to disturb us in the conduct of our lives and actions.’  Belief in miracles, say, may undermine our everyday expectations and, if this is severe enough, it may lead to alienation from the regular, everyday world of sunrises and falling leaves.
As well as disturbing our lives and actions, Hume claims that religion also leads to forms of mental illness. ‘Terror is the primary principle of religion’ and this naturally leads to a melancholic frame of mind, with meditations on Heaven and Hell ‘apt to make a considerable breach in the temper, and to produce that gloom and melancholy, so remarkable in all devout people.’  There are occasional pleasures, but these are ‘fits of excessive enthusiastic joy,’ and these for Hume are not the steady pleasures that bring us happiness. They ‘exhaust … the spirits, always prepar[ing] the way for equal fits of superstitious terror and dejection.’  Religion takes one on a roller coaster of enthusiasm and dejection and such violent mood swings are opposed to the ‘calm and equitable’ state of mind that we seek. The extremes of this can be seen in those who pursue the ‘monkish virtues’ and who reject the social life; theirs is a world of wild enthusiasm and dark melancholia. At various places in his History of England Hume notes the connection between religion and mental illness. Cromwell, for example, was ‘transported to a degree of madness by religious extasies.’  We should thus cultivate ways of thinking that keep us engaged in common life, and in a way that involves ‘that undisturbed philosophical tranquillity, superior to pain, sorrow, anxiety, and each assault of adverse fortune.… And the nearer we can approach in practice to this sublime tranquility and indifference … the more secure enjoyment shall we attain within ourselves.’  In an early essay, Hume ‘laments’ those with ‘delicacy of passion,’ those that are affected strongly by the ups and downs of life: ‘men of such lively passions are apt to be transported beyond all bounds of prudence and discretion, and to take false steps in the conduct of life, which is often irretrievable.’  True philosophy should attempt to ‘take … off the edge from all disorderly passions, and tranquillize … the mind.’  We must therefore step down from the philosophical perspective and embrace the everyday – we must cultivate our garden. In doing so, we avoid the roller coaster emotional ride associated with religion, and various other psychological and physical symptoms characteristic of one plagued by metaphysical and religious questions.
Those tempted by philosophy should take note that:
‘There are … many honest gentlemen, who being always employ’d in their domestic affairs, or amusing themselves in common recreations, have carried their thoughts very little beyond those objects, which are every day expos’d to their senses … I wish we cou’d communicate to our founders of systems [to philosophers] a share of this gross earthy mixture, as an ingredient, which they commonly stand much in need of, and which wou’d serve to temper those fiery particles, of which they are compos’d.’ 
Cultivating our garden is thus a metaphor for the therapeutic role that common life reasoning has with respect to metaphysical and theological worries. And actual gardening, I shall argue, can play a role in promoting the kind of tranquility that Hume claims should be our goal. Before we turn to this it is interesting to note that the philosopher Ludwig Wittgenstein took to gardening as a cure for his psychological problems. In a letter to the architect Paul Engelmann, he says:
I have broken my word. I shall not come your way, at least for the time being.… For in my present dubious state of mind even talking to you – much as I enjoy it – would be no more than a pastime. I was longing for some kind of regulized work which, of all the things I can do in my present condition, is the most nearly bearable, if I am not mistaken. It seems I have found such a job: I have been taken on as an assistant gardener at the Klosterneuberg Monastery for the duration of my holiday. 
Part III: Gardens and Tranquility
Joseph Addison’s (1672–1719) essays in the Spectator impressed Hume and influenced him to write extensively in that style:
‘I know nothing more advantageous than such Essays as these with which I endeavour to entertain the public. In this view, I cannot but consider myself as a kind of resident or ambassador from the dominions of learning to those of conversation; and shall think it my constant duty to promote good correspondence betwixt these two states, which have so great a dependence on each other.’ 
And, in one of these essays, Addison notes the relation between gardens and tranquility:
‘A garden … is naturally apt to fill the mind with calmness and tranquillity, and to lay all its turbulent passions at rest. It gives us a great insight into the contrivance and wisdom of providence, and suggests innumerable subjects for meditation. I cannot but think the very complacency and satisfaction which a man takes in these works of nature, to be a laudable, if not a virtuous habit of mind. For all which reasons I hope you will pardon the length of my present letter.’ 
Voltaire also comments on this aspect of gardening. In a letter from his garden paradise of Les Délices on Lake Geneva, a few months before the completion of Candide, he writes: ‘in our little Romantic country … we are doing here what one should be doing in Paris; we are living in tranquility, we are cultivating literature without any cabals.’  What, then, is the source of the tranquility that Addison and Voltaire describe?
Gardening brings various psychological benefits to the gardener. There are sensory pleasures: the smells, the quiet, the colors. Such pleasures can also lead one to a deeper engagement with the garden: blooms can hold one’s attention, as can trees and expanses of grass; certain corners of the garden may not be beautiful in the traditional sense, yet the crushed snail-shell or the rotting compost can enrapture. A bloom (or, for that matter, the decaying cabbage) can do so, not because one is focused on the prizes it might win (or on the future benefits that one’s compost will bring to the garden); one’s appreciation, rather, is for the thing itself – the fritillaria flower, the pumpkin, or the crumbly brown texture of what was once kitchen waste. David Cooper takes our ability to appreciate the garden in this ‘disinterested’ way to be a virtue,  and William James talks of the psychological benefits of ‘involuntary attention,’ when we find ourselves just looking at the tulip, as opposed to actively looking for the trowel.  Such moments of attention are tranquil ones.
Some have also seen gardens as havens, providing psychological protection from the ‘hostile reminders of human mortality lurking in the terrors of nature.’  William Adams, commenting on French gardens, says: ‘To venture into the forest was to run the risk of losing one’s soul. To reduce the forest to an ordered, tidy ideal world was salvation here on earth.’  The tranquillity of gardens, then, can be seen to lie in their sensory pleasures, in the way that they can hold our attention, and in their protective role.
Further, the tranquillity that gardens and gardening bring should not be seen merely in terms of pleasant feelings or states of consciousness; such tranquillity, rather, is rooted in an account of virtue. Gardening is a moral pursuit, but the kind of morality I have in mind here is not that which focuses on the characterization of acts and intentions as right or wrong; but rather morality in the older tradition of virtue theory. Addison, as we have seen, claims that gardens cultivate ‘a virtuous habit of mind.’ Virtue theorists focus on character traits and not on actions: a pursuit is moral if it inculcates virtuous character traits. Isis Brook, in this volume, has noted this moral dimension to gardening: good gardeners have patience, humility, and generosity. Hume is a kind of virtue theorist. The virtues, for him, are those aspects of character which bring us pleasure, those of which we approve, those which are advantageous for our own peace of mind and for the good of society. Gardening, then, is a virtuous activity, one that is moral, and one that as a consequence brings the tranquillity requisite of a good life.
Gardens, as we all know, take work, and Hume sees industry as a virtue:
‘Men are kept in perpetual occupation, and enjoy, as their reward, the occupation itself, as well as those pleasures which are the fruit of their labour. The mind acquires new vigour; enlarges its powers and faculties; and by an assiduity in honest industry, both satisfies its natural appetites, and prevents the growth of unnatural ones.’ 
The clearing of weeds or the eradication of slugs can seem a task akin to that of Sisyphus, condemned by the gods perpetually to push a boulder up a mountain. We know the weeds and slugs will keep coming back. Albert Camus, the French existentialist philosopher, asks whether Sisyphus is happy, and answers ‘Yes.’ We, Sisyphean gardeners, can hand on heart also answer ‘Yes.’
The Humean gardener, though, must not be too driven. Virtues have associated vices. One can, for example, be too patient; sometimes there is a need for urgency in the garden: one should water the berberis tonight rather than just wait for it to rain. Conversely, Hume stresses the importance of taking your foot off the pedal: ‘human happiness … seems to consist in three ingredients: action, pleasure, and indolence.’  A balance is required and good gardening keeps this balance. The relentless slug exterminator or the manic composter are not gardening well. One, however, who from time to time leans on his spade, puffing on his pipe, is the virtuous gardener. ‘I lean and invite my soul, I lean and loafe at my ease … observing a spear of summer grass.’  In a recent interview, Monty Don, the TV gardener, talks not of loafing, but pottering. Pottering in the garden may not be as industrious as one could be, but ‘pottering and happiness are very likely bedfellows. There is much to be said for it.… To the potterer, the primary benefits of this low level activity are a sense of wellbeing.’ 
In a recent book, Daniel Haybron explores the various dimensions of happiness.  There is first attunement. This is manifest in feelings of tranquility or inner surety (what the Epicureans called ataraxia). As one leans against one’s shed after a heavy bout of digging one feels ‘psychically … at home in one’s life’ – one’s day-to-day anxieties have floated away. Such attunement leads to engagement. One steps inside and becomes engaged in activity – potting on, cleaning one’s tools, organizing one’s seed trays. One can become lost in such activity, unaware of the passage of time, and even of oneself. The psychologist Mihaly Csikszentmihalyi talks of a state of flow in which one loses oneself in this way – the kind of state experienced by the athlete, the knitter, and the dancer.  Before one knows it the sun is setting and one must pack away one’s tools. Lethargy or listlessness have melted away in activity. Zeno, the Stoic, talked of happiness as finding a ‘good flow of life.’ Engagement then leads to endorsement, and here pleasurable feelings are important. One becomes conscious of one’s activity, and perhaps of the productivity of one’s plot or the beauty of one’s blooms.
To be happy, then, is for one’s life to be broadly favorable across these three dimensions of attunement, engagement and endorsement. And Haybron argues that the most important is attunement, the state of tranquility, the state that Hume stresses, and the state that characterizes much of the experience of gardeners. The happiness of gardening is perhaps rarely manifest in feelings of endorsement – blooms and good crops are fleeting; it is more commonly manifest in those foot on the spade, quiet moments. Gardening has its obvious sensory pleasures and rewards, but the therapeutic role of gardens lies not just in these, but in the richer psychological grounds for emotional wellbeing that Haybron explores.
Hume himself was an urbanite: Le Bon David, as he was called in France, was more at home in the salons of Paris than in the garden. Much as he talked of the common life, one cannot really imagine him getting his hands dirty. He also betrays certain negative attitudes to country life. He accuses Cromwell of being engaged in ‘rustic buffoonery’ and calls John Knox a ‘rustic apostle,’ although he does praise ‘agriculture; a profession, which, of all mechanical employments, requires the most reflection and experience.’  Gardens do appear in the Treatise, but only as a source of pride, along with our family, riches, and houses, and to illustrate the workings of the imagination – a poet’s description of the Elysian Fields can be enlivened if he has a view of the garden. I am not suggesting, then, that we would find Hume escaping the psychological dangers of his study in his Parisian roof garden. This essay, rather, is a hybrid of my own love of gardening and admiration for the philosophy of Hume. Philosophical problems do not seem important to me when there are slugs with which to deal. Gardening may cultivate wisdom, but not that of the philosopher; rather, that of the common man.
Philosophers and theologians are a strange unearthly breed. They worry about the existence of the external world and about how an all-perfect being can allow evil, and they spend much of their time anxiously attempting to solve such conundrums. Wittgenstein observes:
I am sitting with a philosopher in the garden; he says again and again ‘I know that that’s a tree,’ pointing to a tree that is near us. Someone else arrives and hears this, and I tell him: ‘This fellow isn’t insane. We are only doing philosophy.’ 
Well, says the Humean gardener, we shouldn’t – we should just get up, prune the tree, perhaps plant some cyclamen around the roots, and then perhaps sit down again.
 C. Jencks, The Garden of Cosmic Speculation (London: Frances Lincoln, 2003), pp. 14, 17, 13.
 E. B. Rogers, Landscape Design: A Cultural and Architectural History (New York: Harry N. Abrams, 2001), p. 238.
 Voltaire, Candide and other Stories (Oxford: Oxford University Press, 2006), p. 22.
 Ibid., p. 11.
 Ibid., p. 88.
 The Complete Works of Voltaire, ed. T. Besterman (Oxford: Voltaire Foundation, 1968), letter no. 11499R.
 D. Hume, Enquiries Concerning Human Understanding and Concerning the Principles of Morals, ed. L. Selby-Bigge, revd. P. Nidditch (Oxford: Oxford University Press, 1975), p. 117.
 Ibid., p. 125.
 D. Hume, Treatise of Human Nature, ed. L. Selby-Bigge, revd. P. Nidditch (Oxford: Oxford University Press, 1978), p. 269.
 Ibid., p. 132.
 Hume, Enquiries, p. 87.
 Ibid., p. 162.
 D. Hume, The History of England, 6 vols. (Indianapolis: Liberty Fund Press, 1983), vol 1, p. 333; vol. 5 p. 12; vol. 6, p. 491.
 D. Hume, Dialogues Concerning Natural Religion, ed. N. Kemp Smith (Indianapolis: Bobs-Merrill, 1947), p. 86; D. Hume, Natural History of Religion, ed. J. Feiser (New York: Macmillan, 1992), pp. 141, 184.
 Hume, Treatise, pp. 271–2.
 Hume, Dialogues, 12.30.
 Hume, History of England, vol. 6, p. 5.
 Hume, Enquiries, p. 256.
 D. Hume, ‘Of the Delicacy of Taste and Passion,’ in Essays: Moral, Political and Literary, ed. E. F. Miller (Indianapolis: Liberty Fund Press, 1985), p. 4.
 ‘The Sceptic,’ in Essays, p. 179n.
 Hume, Treatise, p. 272.
 L. Wittgenstein and P. Engelmann, Letters from Ludwig Wittgenstein, with a Memoir (New York: Horizon Press, 1974), p. 37.
 D. Hume, ‘Of Essay Writing,’ in Essays, p. 535.
 J. Addison, The Spectator, No. 477, September 6, 1712.
 The Complete Works of Voltaire, ed. T. Besterman (Oxford: Voltaire Foundation, 1968), p. 6517.
 D. Cooper, A Philosophy of Gardens (Oxford: Oxford University Press, 2006), p. 94.
 W. James, Psychology (Briefer Course) (Indianapolis: University of Notre Dame Press, 1985).
 W. H. Adams, Gardens Through History: Nature Perfected (New York: Abbeville, 1991), p. 52.
 Ibid., p. 113.
 D. Hume, ‘Of Refinement in the Arts,’ in Essays, p. 270.
 Ibid., p. 269.
 W. Whitman, Leaves of Grass (London: Penguin, 1988), p. 5.
 ‘The Joy of Pottering,’ Giles Wilson, BBC News Magazine, June 1, 2008.
 D. Haybron, The Pursuit of Unhappiness: The Elusive Psychology of Well-Being (Oxford: Oxford University Press, 2008).
 M. Csikszentmihalyi, Flow: The Psychology of Optimum Experience (New York: Harper and Row, 1990).
 Hume, History of England, vol. 3, p. 369; vol. 4, p. 41; vol 6, p. 90. Hume is thought to have had the Roman writer Columella’s treatise on agriculture, De Re Rustica, in his library, as well as two editions of Rev. Adam Dickson’s A Treatise of Agriculture (1765/1770). See The David Hume Library, ed. D. F. Norton and M. J. Norton (Edinburgh: Edinburgh Bibliographical Society, 1996), pp. 83, 87.
 L. Wittgenstein, On Certainty, ed. E. Anscombe and G. H. von Wright (Oxford: Blackwell, 1969), p. 467.
[Originally published in Philosophy for Everyone: Gardening, ed. D. O’Brien, Blackwell, Oxford, 2010]
[image by ‘Dave Catchpole’]