It is a small point, but a telling one; and it is also one which is of surprising relevance to the art of preaching in the twenty-first century. Kennedy's main point about the ministers he had heard and known is that their sermons found their point of departure in the exposition of a given verse or passage of the Bible. All preaching worthy of the name must, of course, do the same.
However, for Kennedy, the evangelicals who filled these Highland pulpits in the nineteenth century were not merely expositors: they were systematic theologians, who could locate the doctrinal content of the text within the orbit of their theological system. They applied all the valid rules of exposition, locating the text in its context, and unfolding its meaning within its historical context and against its canonical background; but they could also show how the doctrine of the text was of a piece with the entire revelation of the Bible.
Kennedy is touching on something vitally important here, and it concerns the relationship between Biblical theology and Systematic theology. At one level, of course, all theology is biblical; that is, it derives its substance and content from the information of the Bible. Theology, the science of knowing God, can only proceed on the basis of revelation; we can know God only as he makes himself known. All theology is dependent on the data of Scripture.
But the terms 'Biblical theology' and 'Systematic theology' are also used in a more technical sense. As subdivisions of theological enquiry, Biblical theology is the discipline of tracing the unfolding revelation of the Bible, from its start to its finish, from its origin to its culmination, from Genesis to Revelation.
In this sense, Biblical theology pays attention to the ways in which God revealed himself, from the primitive forms of self-disclosure in the Old Testament to the final form of his self-revelation in the incarnation of the eternal Son.
One of the classic treatments of the Bible in this way is Geerhardus Vos's Biblical Theology, and it is hard to beat. 'The method of Biblical Theology', Vos says, 'is in the main determined by the principle of historic progression'. That means that the Gospel has come to us in a stream of history, with organic development from the earliest points of revelation through successive epochs and eras, progressing towards the fullness of the New Testament.
Vos cautions against reading back into the text what the authors could not have known, simply because of their location on the timeline of history. The Bible is always conscious of its own anatomy, he says, and we also must pay attention to it. We need to learn to do justice 'to the individual peculiarities of the agents in revelation', and trace the development throughout Scripture.
On the other hand, Systematic Theology takes the same data that Scripture provides, and gathers it together, synthesizing and arranging it topically and thematically, so that we can have an overview of any given subject. We can trawl the Bible to discover what it teaches on the doctrine of the Trinity, or the doctrine of the Church, or even the doctrine of Scripture itself. This is not to impose a structure or system on the Bible from outside; it is simply doing justice to all the strands of revelation, to bring them together into a whole.
Years ago Vos clarified for me the relationship between the two disciplines of Biblical Theology and Systematic Theology. The former constructs the data of the Bible historically, he argues, while the latter constructs these same data logically. Or, to put it at its simplest: Biblical Theology draws a line, while Systematic Theology draws a circle.
So when Kennedy said that the preachers of his day were both expert expositors and outstanding systematicians, he was simply saying that with any text of Scripture they could locate it both on the line of redemptive-historical development and also within the circle of logical systematic arrangement. There was no incongruity between the two approaches: the one safeguarded the organic development of revelation, while the other safeguarded the unity of Scripture.
This is not an outdated issue. In a recent book on theological method ('Always Reforming', edited by Professor Andrew McGowan), Richard Gamble of Pittsburgh has an essay on 'The Relationship between Biblical Theology and Systematic Theology', in which he surveys the uneasy connection which has existed between both approaches. Some have argued that there ought to be strict complementarity between both disciples. Others have argued that Biblical Theology should inform Systematics. Others have charged Biblical Theology with confusing text and event; others have said that Biblical Theology unduly limits revelation, since it leaves no room for extra-historical revelation.
But it would be a mistake to think that the issue is merely academic. I observe that while evangelical publishing houses continue to publish very useful Systematic Theologies – in recent times, for example, we have been treated to classics from Wayne Grudem, Robert Reymond and Norman Geisler – much contemporary evangelical preaching is suspicious of Systematic Theology and takes refuge in its older sister.
So, for example, Old Testament scholar Walter Kaiser argues that we should preach forwards from the Old Testament, limiting ourselves to the plain meaning of the text and the intent and understanding of the original author. That has become the modern approach; our canonical preaching and our insistence that we preach through whole books of the Bible week after week have together fuelled the notion that the principle of progression alone must govern our handling of the facts of God's revelation.
But this cannot be the whole story. The preaching under which I grew up, and which Kennedy both extols and models, was never determined solely by the principle of progression. It was always careful to do justice to the wide arc of biblical truth. Only then can it become truly expository, since there are always two contexts for any verse of Scripture: its immediate context in its book, and its wider context in the whole Bible.
So I am simply making a plea for strong preaching that will do justice both to Biblical Theology and to Systematic Theology. I am reminded of an anecdote of the Rev David Mackenzie of Farr, reminiscing of Dr John Macdonald, Ferintosh: 'I heard William Achina, a godly man in this parish and no mean judge, say that a sermon preached by Mr MacDonald at Reay in 1815 was as complete a compendium of Divinity on the Covenant of Grace as ever he read.'
I just wonder whether our contemporary evangelical sermons convey the whole counsel of God to our hearers in that way.