by Alan Kreider
Did Jesus consider salt a kind of fertilizer? A popular BBC radio program prompted me to investigate that strange notion. And, from that unlikely starting point, I have taken an interpretative journey that has yielded some new insights into one of the most familiar verses in all of the New Testament: ‘You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled underfoot’ (Matt. 5:13).
Jesus’ call to be ‘salt’ and ‘light’ has done more than anything else to justify the social involvements and concerns of English-speaking Christians. Unfortunately, Jesus’ words have become so familiar that they have descended, in many cases, to cliché – a verbal abbreviation that, too often, expresses an inner confusion.
Consider the wide range of interpretations typically offered for ‘salt’. It has been seen as a preservative, a disinfectant, a seasoning, wages, a symbol of covenants, a conveyor of judgment, even a de-icing agent.
The possibilities prompted noted scholar Paul Minear to comment, ‘The extreme variety of interpretations, mostly homiletical, which this image has received over the centuries, indicates the absence of any decisive clue to its original meaning.’
I do not want to capitulate to Minear’s pessimism. But what did Jesus mean by his teaching?
For a long time I agreed with the most widely-held assumption that by ‘salt’ Jesus meant a preservative. But in recent years, I have become increasingly uncomfortable with that. Jesus’ kingdom teachings come across not as defensive but as creative, imagination-inducing, and hope-giving. God’s power and reality flood into the world in new ways in the Messiah. It has grown difficult to accept the notion that Jesus climaxed the Beatitudes with an exhortation to prevent putrefaction.
One day, while idly listening to the BBC radio program ‘Gardener’s Question Time’, a new possibility sprang at me. I learned that during World War II, when potassium fertilizers were in short supply, British farmers resorted to an old technique. They used sodium chloride (table salt) as a fertilizer, especially for beetroot crops.
Salt as fertilizer? An old technique? I set out to check this further. I started with The New International Dictionary of New Testament Theology. In it, Norman Hillyer wrote, ‘Commentators on Matt. 5:13 usually take salt to be a preservative, but the context (in the Greek language tes ges, of the earth) more probably suggests the stimulating property of salt as a fertilizer.’
Where did Hillyer get this curious notion? From Eugene P. Deatrick, no ordinary New Testament exegete. He was head of the Soils Department at West Virginia University. His interpretation grew out of his ‘knowledge of soil chemistry and agricultural history’ (The Biblical Archaeologist, 1962). From Deatrick, my research led me to a category of books in the British Museum that I never thought I would read – nineteenth-century farmers’ encyclopaedias.
From my reading, I concluded that Hillyer and Deatrick were right. In talking about his disciples as salt, Jesus was referring to them as fertilizer rather than preservative. Matthew 5:13 could be translated, ‘You are salt for the soil.’
Salt as fertilizer: does this bear closer examination? Does it make sense of the words Jesus used?
We might first ask if the traditional reading makes sense. ‘Salt’s business is not to provide health,’ D. M. Lloyd-Jones writes confidently in his Studies in the Sermon on the Mount. ‘It is to prevent putrefaction. The principal function of salt is to preserve and to act as an antiseptic. Take, for instance, a piece of meat.’
But Jesus didn’t say, ‘You are the salt of the meat. He was talking about ge. The Greek word ge (the root of geology) has to do with earth, land, ground, soil. The sower who went forth to sow, for example, scattered seed on good ge (Matt. 8:13). Luke’s parallel passage underscores the point. Denatured salt, we read, ‘is fit neither for the ge nor for the manure pile’ (Luke 14:34). The implication is obvious: salty salt is fit for the soil and the manure pile. We’re dealing here not with meat but with fields, crops, and compost.
But does salt really function as a fertilizer? Was the expert on ‘Gardener’s Question Time’ correct? Soils scientists today know all about the unfortunate effects on crops of soil that is too salty. But their predecessors – who did not have access to the artificial fertilizers that have produced the ‘green revolution’ – recognized that salt could be agriculturally beneficial.
One Victorian authority, J. M. Wilson, citing Cato, Virgil and Pliny, asserted, ‘The value of salt, in small quantities, as a manure, appears to have been well-known in ancient times.’ Its disuse in Britain between the 1690s and 1823, he contended, was due to the salt tax imposed by King William III, which raised the price of a bushel of salt forty-fold. But English and Scottish farmers of Wilson’s day were bringing the practice back. Wilson reported that one experiment in Essex showed that a field fertilized with five bushels of salt produced almost as much wheat as one manured with a load of stable dung. Salt, he added, was as good for the dunghill as it was for the soil. ’It improves the quality of excrement for the purposes of manure.’
Salt, in the twentieth century, may have been superseded as a fertilizer. But in the nineteenth century, and probably from ancient times up to that point, salt was a manure – a muck. ‘You,’ says Jesus, ‘are muck for the soil.’
Does salt as fertilizer make sense in the context? First-century Palestine, as a marginal society on the edge of the empire, was suffering the military and economic consequences of the Roman peace. Because of this oppression, Jesus caused intense excitement when, from the start of his ministry, he proclaimed, ‘The kingdom of God is at hand.’ Justice, power, nearness – God’s rule was breaking into history through the Messiah. There was therefore hope – hope of growth (sprouting seeds, expanding leaven) and hope of new possibilities and new answers to intractable questions. In God’s kingdom things would be as they really are, not as they appear to be.
In the Sermon on the Mount, Jesus attempts to make this concrete. Appearances indicate that the rich, laughing, powerful, and successful are heading in the right direction. But the reality which characterizes God’s rule differs from appearances Jesus calls his followers to a ‘better justice’ than that of the Jewish religious leaders (Matt. 5:20). He calls them also to a life style different from the ‘nations’ – from the life style of the Romans (Mart. 5:47; 6:7, 32).
In reality, the Beatitudes people – the poor in spirit, the mourning, the justice-hungry, the peacemaking – are headed toward God’s kingdom. People such as these are open to imaginative insights about such things as anger, divorce, truth-telling, enemy-loving, praying and materialism. Those who think conventionally – the religious leaders and the Romans – won’t like having their appearances stripped away to be replaced by God’s kingdom reality. The result, Jesus predicts, will be conflict.
In the eighth Beatitude, Jesus observes that those who seek justice will be persecuted but will have what is important – God’s kingdom.
Then, turning to his disciples, he alters the address: ‘Blessed are you.’ You, as people of the kingdom’s reality, will be persecuted. But you will be heading in the right direction. For you will have the best of heritages: you will be heirs of the prophets (Matt. 5:11-12).
You are kingdom people. You are heirs of the prophets. You, Jesus summarizes, are salt.
But for what purpose? To p reserve the society of first-century Palestine, keeping the religious and political systems functioning as honestly as possible? Or to fertilize, finding shoots of kingdom life and helping them grow? In the context, I find the latter interpretation infinitely more persuasive.
Assuming that Jesus, in saying ‘you are salt for the earth’, meant fertilizer, what would his disciples have thought he meant? As so often, they probably would have scratched their heads. But some meanings might have been clear to them.
First, as a fertilizer, salt is for scattering. In lumps it can, like any fertilizer, destroy the chemical composition of the soil. If this interpretation is right, Jesus was in part addressing his followers as individuals. From the start, he was anticipating the time when they – through mission and persecution – would be diaspora people, scattered across Palestinian society and into all nations (Matt. 26:31; 28:19). This was necessary. If they remained huddled in one place, they could not fertilize the soil.
Second, as a fertilizer, salt does not exist for itself; it exists for the sake of the shoots of kingdom growth which God has planted. It helps goodness grow. It enables God’s alternative reality to become tangible in people’s experiences. Its aim is not negative – to keep a bad world from becoming worse. Its aim is profoundly positive. It spreads the reality that God wants to save ways of living that are angular to society but congruent with Jesus – and thus profoundly life-giving. Salty disciples encourage that life.
Third, as fertilizer, salt differs from the soil it fertilizes. Distinctiveness – that was the point. Compromise – that was Jesus’ worry. He was concerned that salt could lose its saltiness (literally ‘become foolish’) and blend in with the rest of the soil.
At the end of the Sermon on the Mount, Jesus three times returns to this theme (Matt. 7:13-14, 21-27). The disciples might honour Jesus but choose appearances over reality. They might say, ‘Lord, Lord’, and live not like prophets but like Pharisees and Romans. The consequences, Jesus warned, would be tragic. If his disciples were salt like this, they would be thrown out. They would be no more useful than the rest of the soil on the footpath (Matt. 5:13).
But think of the possibilities for kingdom growth if they resolutely remained salty. What if they, unlike the scribes, loved their enemies! What if they, unlike the Romans, worked for God’s kingdom and justice instead of their own little empires!
How does salt as fertilizer fit our own context? That depends on our view of history and of the good news.
Salt as a preservative appeals to Western readers because it helps make sense of a declining Christendom. The good days are past (the Middle Ages if you’re Catholic, Reformation Europe if you’re Protestant). The world is bad and getting worse (but how comfortably we accept its perquisites). Our calling as salt is to stop the rot. We are called to permeate the structures of society, work hard, do our duty, be evangelistically active, be honest in our dealings, never smutty or sacrilegious. In a commentary on Matthew, R. V. G. Tasker summarizes our mission as being ‘a moral disinfectant in a world where moral standards are low, constantly changing, or nonexistent.’
Imagine another view which queries how Christian the values of ‘Christian Europe’ actually were and thus does not need to be defensive. The justice, power, and nearness of God’s kingdom are breaking in not to preserve ‘Christian’ society but to make men and women, their churches and even aspects of society congruent with Christ. This, no less than the preserving view, requires hard work, duty-doing, and the rest. But it also invites us to engage in new thinking. It urges us to commit ourselves to change. It assumes that God through the Spirit is doing new things. Jesus – by his life and teaching – is the one who defines this newness. Our time is a time not of rear-guard action but of mission.
Within the existing structures, the only way that there is any Christian impact is if believers function there like Jesus. Does it sound ridiculous when a British Chancellor of the Exchequer talks about ‘forgiving debts’? Or when a Christian psychiatrist calls for a ‘poor-in-spirit presidency’ in the United States? Can there be a politics of the Sermon on the Mount? Or a corporate strategy, or a housing policy of the Sermon on the Mount? Can we be genuinely Jesus-like and keep our jobs? Possibly. But it will never be easy. At times, the only way to make a Jesus-like impact may be to begin new initiatives, to create new structures.
Certainly Christians, as a significant minority, cannot do everything. But strategically scattered, we can be sources of liberated imagination. We can help goodness grow.
This article was published in Macquarie Christian Studies Institute: Think Piece No 11 (June 2005); originally published in a longer version in The Other Side (March/April 1989), pp34-37