The Trouble With Trajectories

You have to be careful with trajectories. Just ask anyone who has to predict things: economists, politicians, weather forecasters. The general rule is, the fewer data points you have, the more cautious you have to be. So if you have loads of data, you can predict things fairly confidently, but if you try to draw trajectories off the back of two or three snapshots, you can end up making a real pig's ear of things. I used to be a management consultant, so I ought to know.

You have to be especially careful when there are underlying causes of a trend that may subsequently change. Imagine, for instance, that you are appraising a company that has been growing its turnover by 20% for five years. You might predict, on the basis of the existing trajectory, that it would continue to grow by 20% for the next five years. But if that growth had been caused by buying other similar companies in its sector, and the list of available similar companies was running out, you could make some very bad forecasts if you didn’t realise that. The progression, in that scenario, was not a trajectory at all, in the sense of a trend which could be extrapolated forwards, but a series of step changes in the company’s story which weren’t going to be repeated - so when those step changes stopped, so did the growth.
Biblical interpreters should take note. There are all sorts of theologians arguing that there are “trajectories” in Scripture - particularly with reference to ethical issues that contemporary culture finds unpalatable (slavery, gender roles, smacking children, divorce and remarriage). But frequently, these progressions are not trajectories at all, but the results of step changes in the biblical story which won’t be repeated. So when those step changes in the biblical story stop, as our view of the shape of God’s story indicates they have - there is no change in covenants/dispensations/‘acts in the play’ between Acts 28 and the 21st Century - then extrapolating the trend forwards becomes very tenuous.
Slavery often carries the load for this type of approach. In a trajectory hermeneutic, much is made of the gradual progression from slavery being permitted in the Torah, through to being challenged in the New Testament period, and then finally abolished in the nineteenth century. But as I’ve argued before, this very neat description is not really accurate. The New Testament (1) bans enslaving others, (2) encourages slaves to take their freedom if given the opportunity, (3) tells slaves who don’t get that opportunity to serve their master as if serving the Lord, (4) tells many Christian masters to treat their slaves in a way that subverts the institution of slavery altogether, (5) and tells one, Philemon, to manumit his former slave - and none of these instructions has been superseded by the passing of time. On the contrary, they all remain applicable to the modern, global church, just as they were when Paul first wrote them, even if those of us in the UK can often forget that.
I’ve written plenty on gender recently, and don’t really want to wade into the choppy waters of smacking children or divorce and remarriage at this point, so I won’t go through the equivalent process for each issue where there is said to be a “trajectory”. For now, it should be enough to raise awareness of the trouble with trajectories, and suggest that whether we operate within a covenantal, dispensational, or five act play framework, we should not see the changes between the first and twenty-first centuries as analogous to those between (say) the Mosaic and New covenants. Imagine if we did. First no adultery, then no looking lustfully, then…no looking at all?

Andrew’s next book, If God Then What? Wondering Aloud about Truth, Origins and Redemption, will be released in April, published by IVP.

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