The One remains, the many change and pass;
Heaven's light forever shines, Earth's shadows fly;
Life, like a dome of many-coloured glass,
Stains the white radiance of Eternity,
Until Death tramples it to fragments.
(Shelley)
At its widest, ‘pluralism’ signifies simply the variety of life, the teeming multitude of forms and entities, the many different properties that living beings manifest. Life is not everywhere the same but impressively differentiated, and without it eternity would be all of a piece, uniform. That is enough for life to stain the white radiance of eternity. But within the multiplicity of specifically human life there are not merely differences. There are tensions, oppositions, conflicts. In contemporary philosophical debate ‘pluralism’ then comes to signify one problematic aspect of this. Groups of people have perhaps always subscribed to very different values, and in consequence favoured very different forms of behaviour from one another, at least on a global scale. But the groups are no longer geographically separated: we live in distinct but overlapping cultures, and get in one another's way to a far greater extent than previously. Shelley's ordered image of the dome may then seem inappropriate, and it may seem unnecessary for death to trample it to fragments. Life is already fragmented, and the practical problem facing us as living creatures is to go beyond the fragments, to achieve at least a modus vivendi in the light of all our differences and incompatibilities even if not the orderliness and cohesion of a dome. Somehow, we have to live together. That is a practical problem which confronts us at every level, as members of families, neighbourhoods, departments, countries and increasingly simply as members of a world-wide human race.