For many Christians, the words “philosophical” and “systematic” do not have the best of connotations. “Philosophy” reminds them, perhaps, of certain philosophers who have mocked Christianity, such as Nietzsche or several of the New Atheists. Likewise, “systematic” might conjure up images of theologians whose “system” subverts or overrides the biblical testimony, or whose books are so dense and technical that one wonders who could possibly understand them. And while these negative impressions might sometimes have been earned by practitioners of these two disciplines, I think that both disciplines can be helpful tools in a theologian’s toolbox, if treated appropriately. I will give you a hint: I am going to suggest that it will be helpful for the church if professional theologians will do systematic theology in such a manner that they move a step or two away from philosophical theology and step or two toward biblical theology.
The Nature and Legitimacy of Philosophical Theology
There are various ways of conceiving the task of philosophical theology, but it will suffice here to say that philosophical theology is the appropriation of philosophical tools for the task of theology. Such appropriation has been evident since the earliest days of church history, in which the church found itself needing to interact with a language and a Greco-Roman framework of thought that were not designed with the needs of Christian theology in mind. McGrath writes, “On the one hand, it was necessary to go beyond the insights of scripture in order to meet the new intellectual challenges faced by the Christian communities; on the other, it was necessary to ensure that these extensions of the scriptural vocabulary and conceptual framework were consonant with its central insights.” Indeed theologians in the present era wrestle with the same challenge, acknowledge that some level of philosophical theology is unavoidable, and find appropriate ways to draw upon his context’s conceptual languages and frameworks.
The Nature and Legitimacy of Systematic Theology
As with biblical and philosophical theology, there are more than a few ways to conceive systematic theology. For the purpose of this chapter, we will define systematic theology as a discipline which draws upon the biblical narrative in order to conceptualize and articulate the biblical faith in a comprehensive, well-proportioned, and unified manner for a particular cultural context. Because it is done for a particular context, it often conceptualizes and articulates the biblical faith in relation to questions that arise outside of the text, and with categories that are not explicitly found in the text. It is “systematic,” by nature of the fact that it is organized based upon a set of presuppositions, and also on the basis of pedagogical and presentational concerns. A faithfully biblical systematic theology will be “systematic” without flouting the biblical ordering, lopping off awkward biblical data, or otherwise relegating Scripture to a secondary status. It will seek to construct systematic conceptions of the biblical material that arise comfortably from the biblical narrative, resonate with its core teachings, take into account all of the biblical data, and recognize its own secondary status in relation to Scripture. Further, we note that faithful theologians will not read the Bible in order to construct “great systematic theologies.” Rather we construct systematic theologies that help us read the Bible better, systems that lead us to deeper and richer exegesis. Scripture is primary, while systematic renderings of it are secondary.
The Relationship of Systematic Theology to Philosophical Theology and Biblical Theology.
Evangelical systematic theologians generally sustain conversation, at some level, with both biblical theologians and philosophical theologians. Systematic theologians are sometimes dependent upon philosophical theology for certain concepts with which to articulate the Christian message. Rational representation of the Christian message requires concepts, which are abstractions of the more concrete and historical biblical narrative(s). Philosophical theology provides those concepts, and has done so throughout church history. For example, the early church fathers spoke of Christ as being homoousios with (or, “of the same essence as”) the Father. They did so in order to speak clearly and in a common language within their cultural context. Philosophical concepts can function as a sort of intellectual shorthand which allows for more direct apprehension than can be had from the sprawling narrative of Scripture, composed as it is of narrative, poetry, prose, and other genres.
However, these concepts can undermine the Bible unless the theologian defines those concepts biblically, filling them with Christian meaning drawn from the biblical narrative. In his seminal article on this topic, Michael Williams writes, “I want to argue this precise point: the biblical narrative structure, the story of God’s relationship with his creation-from Adam to Christ crucified and resurrected to Christ triumphant in the restoration of all things in the kingdom of God-forms the regulative principle and interpretive key for systematic theology no less than it does for biblical theology. This suggests that a systematic theology that is oriented to the biblical narrative and scriptural ways of knowing ought to be redemptively-historically grounded rather than ordered to a cultural convention of rationality or an extra-biblical conception of system.”
If the concepts drawn from philosophical theology are ever “cut free” from the narrative and allowed to “float” on their own, the result will be a distortion or subversion of the biblical teaching. For example, Christian theologians have drawn upon Aristotelian philosophy in order to conceive and articulate God’s attributes in terms of God’s “pure actuality,” “simplicity,” “aseity,” “necessity,” and so forth. But if God is described merely in those terms, without those terms being defined by the biblical witness about God and his mighty acts in history, we have not understood who God is. We have contemplated some abstractions about a purported deity, but we have not understood or embraced the God of Israel who alone can save. For this reason, we affirm that biblical theology, rather than any culturally conditioned philosophical framework, is the home environment of systematic theology.
Theology’s often inappropriate relationship with philosophical theology began in the patristic period, but gained steam in the medieval period, as the scholastic method fostered an impulse toward abstraction. Theology became an exercise in abstract, metaphysical knowledge of God divorced from the concrete particularity of the historical narrative. In fact, the Reformers sought to reform theology on this exact point. Luther’s “theology of the cross” was an attempt to assert the priority of the narrative over metaphysics. “Luther’s fundamental point . . . is that the narrative of the crucified Christ must be interpreted on the basis of a framework established by that narrative itself, rather than upon the basis of an imposed alien framework.” The theologian of the cross is the one who allows his conceptual framework to arise naturally from the biblical narrative rather than vice-versa, interpreting the biblical narrative on the basis of a preconceived system.
McGrath, The Genesis of Doctrine
 This definition draws upon, but modifies and expands, the definition given by John Webster, that “systematic theology aims at a comprehensive, well-proportioned, and unified conceptual representation of Christian teaching.” Webster, “Introduction: Systematic Theology,”12.
 Michael Williams, “Systematic Theology as a Biblical Discipline,” in All for Jesus: A Celebration of the 50th Anniversary of Covenant Theological Seminary, ed. Robert A. Peterson and Sean Michael Lucas (Fearn, Tain, UK: Christian Focus Publications, 2006), 167-196.
 McGrath, The Genesis of Doctrine, 65.