When Dr Johnson observed that 'when a man knows he is to be hanged it concentrates the mind wonderfully', he might have had the example of Boethius in mind. Between about AD 524 and 526, Boethius, a middle-aged Roman aristocrat, scholar, philosopher and Christian theologian, and one of the most influential members of the court of Theodoric, the Ostrogothic ruler of Italy, was arrested for alleged treasonable activities against the king.

During his confinement at Pavia in northern Italy, Boethius, who faced the death-penalty, wrote his masterpiece, The Consolation of Philosophy, a work in which he considers universal issues such as the nature of justice, the problem of evil in a world controlled by God's providential plan, and the workings of Fortune and free will. The book takes the form of a dialogue between Philosophy, who is personified as a woman, and the hapless Boethius, a prisoner bemoaning his fate. Philosophy sees it as her task to wean Boethius (or more correctly 'the prisoner' - Boethius's persona in the work) away from his destructive self-pity and to apply the balm of philosophical ointment to remedy his distress, which she views as a type of sickness. The book, which Edward Gibbon described as a 'golden volume not unworthy of the leisure of Plato', became one of the most influential works of the Middle Ages and beyond. It was translated by, among others, King Alfred the Great, Chaucer and Elizabeth I. Dante, an avid reader of Boethius, refers to him in the Paradiso as 'the holy soul who brings to light the world's deceitfulness'.

Each of the Consolation's five books consists of prose alternating with poems (a form known as Menippean after the Satires of the third-century BC Greek writer Menippus of Gadara). In all there are thirty-nine poems: thirty-five of them are addressed by Philosophy to Boethius, while the remaining four are spoken by the prisoner himself. The poems serve to introduce, reflect, enlarge upon and emphasise the themes that the prose sections treat discursively.

Although the poems are part of a unified whole, they also form a coherent thematic sequence by themselves. The journey they describe starts with Boethius's abject, almost

theatrical, distress and ends with Philosophy's words about the dignity of human beings and how their vertical body shape suggests they should be looking up towards the heavenly realm above, not down at the earth like the lower animals. Along the way there are poems about God and love, the falseness of earthly riches, the transience of human honours, the ascent of the soul to the realm of light, the slipperiness of Fortune, the laws of chance, and the nature of the mind and its modes of perception. By the end, the reader, like Bunyan's Pilgrim, has trekked through Boethius's slough of despond and come out the other side, spirits lifted by the sense of transcendence that Philosophy has instilled. Boethius's consolation, is Everyman's.

In Prison

I used to relish scribbling poetry.
But now I'm stuck with dirges born of sadness.
Look how the Muses, dishevelled by distress,
prompt elegies that only make me cry.

At least they weren't put off by any fears
from being my companions on this journey.
They were the best thing of my salad days:
now they console me in my sad last years.

A sudden spate of suffering and I'm old.
Decrepit from the tyrannous rule of anguish;
...