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What Is Philosophy?

J.P. Moreland and William Lane Craig

Where am I or What?

From what causes do I derive my existence,

and to what condition shall I return?

Whose favor shall I court, and whose anger must I dread?

What beings surround me?

And on whom Have I any influence, or who have any influence on me?

I am confounded with all these questions,

and begin to fancy myself in the most deplorable condition imaginable,

inviron’d with the deepest darkness,

and utterly deprived of the use of every member and faculty.


Not every problem, nor every thesis, should be examined,

but only one which might puzzle one of those who need argument.


Ought not a Minister to have,

First, a good understanding, a clear apprehension, a sound judgment,

and a capacity of reasoningwith some closeness. . . .

Is not some acquaintance with what has been termed the second part of logic,

(metaphysics), if not so necessary as [logic itself], yet highly expedient?

Should not a Minister be acquainted with at least the

general grounds of natural philosophy?



You are about to embark on an exciting and fascinating journey—the philosophical exploration of some of life’s most important ideas, ideas about reality, God, the soul, knowledge and truth, goodness, and much, much more. Make no mistake about it. Ideas matter. The ideas one really believes largely determine the kind of person one becomes. Everyone has a philosophy of life. That is not optional. What is optional and, thus, of extreme importance is the adequacy of one’s philosophy of life. Are one’s views rational or irrational, true or false, carefully formed and precise or conveniently formed and fuzzy? Are they conducive to human flourishing or do they cater to one’s fallen nature? Are they honoring or dishonoring to the triune God? The discipline of philosophy can be of great help in aiding someone in the search for an increasingly rich and robust philosophy of life.

For centuries, people have recognized the importance of philosophy. In particular, throughout the history of Christianity, philosophy has played an important role in the life of the church and the spread and defense of the gospel of Christ. The great theologian Augustine (354-430) summarized the views of many early church fathers when he said, “We must show our Scriptures not to be in conflict with whatever [our critics] can demonstrate about the nature of things from reliable sources.”1 Philosophy was the main tool Augustine used in this task. In 1756, John Wesley delivered an address to a group of men preparing for ministry. He exhorted them to acquire skills which today are often neglected in seminary education but which seminaries would do well to reinstate. And much of what he said is sound advice for all Christians. For Wesley, among the factors crucial for the service of Christ was a tolerable mastery of logic and philosophy in general.

Unfortunately, today things are different. Theologian R. C. Sproul has called this the most anti-intellectual period in the history of the church, and former Secretary-General of the United Nations and Christian statesman Charles Malik warns that the greatest danger facing modern evangelicalism is a lack of cultivation of the mind, especially as it relates to philosophy.

This trend within the church is coupled with two unfortunate features of Western culture: the rampant pragmatism in society with the concomitant devaluation of the humanities in university life and the nonexistence of philosophy in our precollege educational curricula. The result is that philosophy departments are endangered species in Christian colleges and seminaries, and serious philosophical reflection is virtually absent from most church fellowships. This, in turn, has contributed to intellectual shallowness and a lack of cultural discernment in the body of Christ.

But is philosophy really that important for the life, health and witness of the church? Are God’s people not warned in Scripture itself to avoid philosophy and worldly wisdom? And just what is philosophy, anyway? How does it help believers form an integrated Christian worldview? How does philosophy relate to other disciplines taught at the university?


Scholars generally are agreed that there is no airtight definition that expresses a

set of necessary and sufficient conditions for classifying some activity as philosophical, conditions which all and only philosophy satisfies. But this should not be troubling. In general, one does not need a definition of something before one can know features of the thing in question and recognize examples of it. One can recognize examples of historical study, love, a person, art, matter, sport and a host of other things without possessing an airtight definition. Nevertheless, definitions are useful, and a reasonably adequate definition of philosophy can be provided.

How might someone go about formulating such a definition? Three ways suggest themselves. First one could focus on the etymology of the word philosophy. The word comes from two Greek words philein, “to love,” and sophia, “wisdom.” Thus a philosopher is a lover of wisdom. Socrates held that the unexamined life is not worth living, and the ancient Greek philosophers sought wisdom regarding truth, knowledge, beauty and goodness. In this sense, then, philosophy is the attempt to think hard about life, the world as a whole and the things that matter most in order to secure knowledge and wisdom about these matters. Accordingly, philosophy may be defined as the attempt to think rationally and critically about life’s most important questions in order to obtain knowledge and wisdom about them. Philosophy can help someone form a rationally justified, true worldview, that is, an ordered set of propositions that one believes, especially propositions about life’s most important questions.

Second, our understanding of philosophy will be enhanced if we observe that philosophy often functions as a second-order discipline. For example, biology is a first-order discipline that studies living organisms, but philosophy is a second-order discipline that studies biology. In general, it is possible have a philosophy of x, where x can be any discipline whatever; for example, law, mathematics, education, science, government, medicine, history or literature. When philosophers examine another discipline to formulate a philosophy of that field, they ask normative questions about that discipline (e.g., questions about what one ought and ought not believe in that discipline and why), analyze and criticize the assumptions underlying it, clarify the concepts within it and integrate that discipline with other fields.

Consider biology again. Philosophers ask questions like these: Is there an external world that is knowable and, if so, how does one know it? What is life, and how does it differ from nonlife? How should someone form, test and use scientific theories and laws? Is it morally permissible to experiment on living things? When biologists talk about information in DNA, how should we understand this talk? How does the biological notion of being a member of the kind Homo sapiens relate to the theological notion of being made in the image of God or to the metaphysical notion of being a person with legal/moral rights? These questions are all philosophical in nature, and by examining them it becomes evident that philosophers ask and seek to answer presuppositional, normative, conceptual and integrative questions about other fields of study. Thus, by its very nature philosophy is, perhaps, the most important foundational discipline in the task of integrating Christian theology with other fields of study. This claim is examined in more detail later.

One more observation is important. Because philosophy operates at a presuppositional level by clarifying and justifying the presuppositions of a discipline, philosophy is the only field of study that has no unquestioned assumptions within its own domain. In other words, philosophy is a self-referential discipline, for questions about the definition, justification and methodology of philosophy are themselves philosophical in nature. Philosophers keep the books on everyone, including themselves. The justification of the assumptions of any discipline, including philosophy, is largely a philosophical matter.

A third way to characterize philosophy is simply to list the various subbranches of philosophy. In addition to the different second-order branches of philosophy, such as philosophy of science (see part four) or religion (see part six), a number of standard areas of study are first-order parts of philosophy. For example, logic (see chap. 2) investigates the principles of right reasoning and focuses on questions such as When can a conclusion legitimately be drawn from premises and why? Epistemology is the study of knowledge and justified belief (see part two). What is knowledge? Can we have it? How do we know things and justify our beliefs? What are the kinds of things we can know? Metaphysics is the study of being or reality (see part three). Here are some metaphysical questions: What does it mean for something to exist? What are the ultimate kinds of things that exist? What is a substance? What is a property? Is matter real? Is mind real? What are space, time and causation? What is linguistic meaning? Value theory is the study of value; for example, ethical value (see part five) and aesthetic value. What does it mean to say something is right or wrong, beautiful or ugly? How do we justify our beliefs in these areas?

These subbranches combine with the various second-order areas of investigation to constitute the subject matter of philosophy. In these areas of study, philosophy serves both a critical and a constructive function. Philosophy is critical because it examines assumptions, asks questions of justification, seeks to clarify and analyze concepts, and so on. Philosophy is constructive because it attempts to provide synoptic vision; that is, it seeks to organize all relevant facts into a rational system and speculate about the formation and justification of general worldviews. Chapter two includes an examination of the role of philosophy in forming and assessing a worldview.

We have briefly examined the different aspects of philosophy in order to get a better grasp on what the discipline is and the sorts of issues within its purview. Let us now look at the importance of philosophy for the Christian life in general and the Christian university in particular.


The history of the church reveals that philosophy has always played a crucial role in the nurture of believers and in the proclamation of a Christian worldview in general and the gospel in particular. The first universities in Europe were, of course, Christian, and the study of philosophy was considered of central importance to the health and vitality of the university and the Christian life. This is no less true today. In fact, there are at least seven reasons why philosophy is crucial to the texture, curricula and mission of the Christian university and the development of a robust Christian life.

First, philosophy is an aid in the task of apologetics. Apologetics is the task of giving a reasoned defense of Christian theism in light of objections raised against it and of offering positive evidence on its behalf. Scripture commands us to engage in apologetics (see 1 Pet 3:15; Jude 3). The Old Testament prophets often appealed to broad arguments from the nature of the world to justify the religion of Israel. For example, they would ridicule pagan idols for their frailty and smallness. The world is too big, they claimed, to have been made by something that small (see Is 44—45). Arguments like this assume a philosophical position on the nature of causation; for example, that an effect (the world) cannot come from something of lesser power than itself (the idol). Again, the Old Testament prophets often appealed to general principles of moral reasoning in criticizing the immorality of pagan nations (e.g., Amos 1—2). Arguments such as this utilize natural moral law and general philosophical principles of moral reasoning.

In the New Testament, the apostles used philosophical argumentation and reasoning to proclaim Christ to unbelievers (see Acts 17:2-4, 17-31; 18:4; 19:8). Their practice was consistent with that of the Old Testament prophets in this regard. Philosophy aids a person in stating arguments for God’s existence. It also helps one clarify and defend a broad view of what it is for something to exist so as to include nonphysical and nonspatiotemporal entities; for example, God, angels and perhaps disembodied souls. When an objection against Christianity comes from some discipline of study, that objection almost always involves the use of philosophy. When Freud argued against religion on the grounds that our ideas of God are mere illusions, grounded in and caused by our fears and the need for a father figure, his attack, while rooted in psychology, nevertheless involved the discipline of philosophy. He was considering the basic question of how the source of our belief relates to our justification for that belief.

Second, philosophy aids the church in its task of polemics. Whereas apologetics involves the defense of Christian theism, polemics is the task of criticizing and refuting alternative views of the world. For example, in the field of artificial intelligence and cognitive psychology there is a tendency to view a human being in physicalist terms, that is, as a complex physical system. Despite protests to the contrary from some Christian thinkers, dualism (the view that we are composed of both a physical and a mental entity) is the view taught in Scripture (see 2 Cor 5:1-8; Phil 1:21-24). Part of the task of a believer working in the areas of artificial intelligence or cognitive psychology is to develop a critique of a purely physicalist vision of being human, and this task includes issues in the philosophy of mind (see chaps. 11-12).

Third, philosophy is a central expression of the image of God in us. It is very difficult to come up with an airtight definition of the image of God, but most theologians have agreed that it includes the ability to engage in abstract reasoning, especially in areas having to do with ethical, religious and philosophical issues. God himself is a rational being, and humans are made like him in this respect. This is one of the reasons humans are commanded to love God with all of their minds (Mt 22:37). Since philosophy, like religion, is a discipline that chiefly focuses on ultimate questions near the very heart of existence, then philosophical reflection about God’s special and general revelation can be part of loving him and thinking his thoughts after him.

Fourth, philosophy permeates systematic theology and serves as its handmaid in several ways. Philosophy helps to add clarity to the concepts of systematic theology. For example, philosophers help to clarify the different attributes of God; they can show that the doctrines of the Trinity and the Incarnation are not contradictory; they can shed light on the nature of human freedom, and so on.

Further, philosophy can help to extend biblical teaching into areas where the Bible is not explicit. For example, several areas currently under discussion in medical ethics (active/passive euthanasia, genetic screening, withholding artificial food and hydration, artificial insemination) are not explicitly mentioned in Scripture. The philosopher can, however, take the language and doctrines of the Bible and appropriately recast them in the relevant categories under discussion. In this way the philosopher can help to shed biblical light on an issue not explicitly mentioned in Scripture by providing conceptual categories and analysis that fit the situation and preserve the tenor and substance of biblical teaching.

Fifth, the discipline of philosophy can facilitate the spiritual discipline of study. Study is itself a spiritual discipline, and the very act of study can change the self. One who undergoes the discipline of study lives through certain types of experiences where certain skills are developed through habitual study: framing an issue, solving problems, learning how to weigh evidence and eliminate irrelevant factors, cultivating the ability to see important distinctions instead of blurring them, and so on. The discipline of study also aids in the development of certain virtues and values; for example, a desire for the truth, honesty with data, an openness to criticism, self-reflection and an ability to get along nondefensively with those who differ with one.

Of course, the discipline of study is not unique to philosophy. But philosophy is among the most rigorous of fields, and its approach and subject matter are so central to life, close to religion and foundational to other fields of investigation, that the discipline of philosophical study can aid someone in the pursuit of truth in any other area of life or university study.

Sixth, the discipline of philosophy can enhance the boldness and self-image of the Christian community in general. It is well known that a group, especially a minority group, will be vital and active only if it feels good about itself in comparison with outsiders. Further, there will be more tolerance of internal group differences, and thus more harmony, when a group feels comfortable toward outsiders.

In a fascinating study, John G. Gager argues that the early church faced intellectual and cultural ridicule from Romans and Greeks. This ridicule threatened internal cohesion within the church and its evangelistic boldness toward unbelievers. Gager argues that it was primarily the presence of philosophers and apologists within the church that enhanced the self-image of the Christian community because these early scholars showed that the Christian community was just as rich intellectually and culturally as was the pagan culture surrounding it. Says Gager:


Whether or not the apologists persuaded pagan critics to revise their view of Christians as illiterate fools, they succeeded in projecting for the group as a whole a favorable image of itself as the embodiment of true wisdom and piety. . . . Whatever we may say about the expressed purpose of these apologies, their latent function was not so much to change the pagan image of Christians as to prevent that image from being internalized by Christians themselves.2

Gager’s point could and should be applied to the value of Christian scholarship in general, but the applicability of his remarks to the field of philosophy should be obvious. Historically, philosophy has been the main discipline that has aided the church in its intellectual relationship with unbelievers. Because of the very nature of philosophy itself—its areas of study and their importance for answering ultimate questions, the questions it asks and answers, its closeness to theology—the potential of this discipline for enhancing the self-respect of the believing community is enormous.

It seems clear that evangelicalism in America is having a serious self-image problem. The reasons for this are no doubt varied, but it can hardly be an accident that the average Bible college has no philosophy department, and many evangelical seminaries do not offer serious, formal training in philosophy and apologetics beyond a course here and there.

Seventh, the discipline of philosophy is absolutely essential for the task of integration. To integrate means to blend or form into a whole. In this sense, integration occurs when one’s theological beliefs, primarily rooted in Scripture, are blended and unified with propositions judged as rational from other sources into a coherent, intellectually adequate Christian worldview. Since this will be the main topic of discussion below, little need be added at this point except to note that the need for integration occurs in at least three ways.

For one thing, the believing community needs to draw from all areas of knowledge in forming an integrated Christian worldview consistent with Scripture. Second, a person grows to maturity to the extent that he or she becomes an integrated, unfragmented self, and one of the ways to become an integrated person is to have the various aspects of one’s intellectual life in harmony. If Smith believes one thing in church and another thing in the lab or office, he will to that extent be a fragmented, dichotomized individual wherein Christ can dwell only in a shrinking religious compartment of his life. Finally, when the gospel confronts a new culture, Christian theology must be related to that culture in a way that is at once sensitive to the culture and faithful to Scripture. Such a task will include questions of value, knowledge and thought forms, and these questions essentially involve philosophical clarification and comment.

These are some of the reasons why the church has always found philosophy to be necessary. C. S. Lewis once remarked that “to be ignorant and simple now—not to be able to meet the enemies on their own ground—would be to throw down our weapons, and to betray our uneducated brethren who have, under God, no defence but us against the intellectual attacks of the heathen. Good philosophy must exist, if for no other reason, because bad philosophy needs to be answered.”3

The great social critic William Wilberforce (1759-1833) was a man of deep devotion to God and great passion for practical ministry. But Wilberforce saw the value of philosophy and apologetics even for the training of children in the church! Queried Wilberforce, “In an age in which infidelity abounds, do we observe [believers] carefully instructing their children in the principles of faith they profess? Or do they furnish their children with arguments for the defense of that faith?”4 Sources for similar attitudes could be cited throughout the history of the church: Justin Martyr, Augustine, Anselm, Aquinas, Calvin, Jonathan Edwards, John Wesley, Francis Schaeffer, Carl Henry. Nevertheless, there is a general perception among many believers that philosophy is intrinsically hostile to the Christian faith and should not be of concern to believers. There are at least four reasons frequently cited for such an attitude.

First, the claim is made that human depravity has made the mind so darkened that the noetic effects of sin, that is, sin’s effect on the mind, render the human intellect incapable of knowing truth. However, this claim is an exaggeration. The Fall brought about the perversion of human faculties, but it did not destroy those faculties. Human reasoning abilities are affected but not eliminated. This can be seen in the fact that the writers of Scripture often appeal to the minds of unbelievers by citing evidence on behalf of their claims, using logical inferences in building their case and speaking in the language and thought forms of those outside the faith.

Second, it is sometimes claimed that faith and reason are hostile to each other, and whatever is of reason cannot be of faith. But this represents misunderstanding of the biblical concept of faith. The biblical notion of faith includes three components: notitia (understanding the content of the Christian faith), fiducia (trust) and assensus (the assent of the intellect to the truth of some proposition). Trust is based on understanding, knowledge and the intellect’s assent to truth. Belief in rests on belief that. One is called to trust in what he or she has reason to give intellectual assent (assensus) to. In Scripture, faith involves placing trust in what you have reason to believe is true. Faith is not a blind, irrational leap into the dark. So faith and reason cooperate on a biblical view of faith. They are not intrinsically hostile.

Third, some cite Colossians 2:8 as evidence against philosophy: “See to it that no one takes you captive through hollow and deceptive philosophy, which depends on human tradition and the basic principles of this world rather than on Christ” (NIV). However, on an investigation of the structure of the verse, it becomes clear that philosophy in general was not the focus. Rather, the Greek grammar indicates that “hollow and deceptive” go together with “philosophy,” that is, vain and hostile philosophy was the subject of discussion, not philosophy per se. In the context of Colossians, Paul was warning the church not to form and base its doctrinal views according to a philosophical system hostile to orthodoxy. His remarks were a simple warning not to embrace heresy. They were not meant in context to represent the apostle’s views of philosophy as a discipline of study. Those views are not relevant to the context and do not square with the grammar of the passage.

Finally, 1 Corinthians 1—2 is cited as evidence against philosophy. Here Paul argues against the wisdom of the world and reminds his readers that he did not visit them with persuasive words of wisdom. But again, this passage must be understood in context. For one thing, if it is an indictment against argumentation and philosophical reason, then it contradicts Paul’s own practices in Acts and his explicit appeal to argument and evidence on behalf of the resurrection in 1 Corinthians 15. It also contradicts other passages (e.g., 1 Pet 3:15) as well as the practice of Old Testament prophets and preachers.

The passage is better seen as a condemnation of the false, prideful use of reason, not of reason itself. It is hubris (pride) that is in view, not nous (mind). The passage may also be a condemnation of Greek rhetoric. Greek orators prided themselves in possessing “persuasive words of wisdom,” and it was their practice to persuade a crowd of any side of an issue for the right price. They did not base their persuasion on rational considerations, but on speaking ability, thus bypassing issues of substance. Paul is most likely contrasting himself with Greek rhetoricians.

Paul could also be making the claim that the content of the gospel cannot be deduced from some set of first principles by pure reason. Thus the gospel of salvation could never have been discovered by philosophy, but had to be revealed by the biblical God who acts in history. So the passage may be showing the inadequacy of pure reason to deduce the gospel from abstract principles, not its inability to argue for the truth.

We have seen that there are good reasons why the church has historically valued the role of philosophy in her life and mission, and reasons to the contrary are inadequate. It is time now to turn to the issue of the role of philosophy in the integrative task of forming a Christian worldview.


It may be helpful to begin this section by listing examples of issues in a field of study that naturally suggest the relevance of philosophical reflection and where someone in that field of study may, inadvertently, don a philosopher’s cap.


1.       A biblical exegete becomes aware of how much her own cultural background shapes what she can see in the biblical text, and she begins to wonder whether meanings might not reside in the interpretation of a text and not in the text itself. She also wonders if certain methodologies may be inappropriate given the nature of the Bible as revelation.


2.      A psychologist reads the literature regarding identical twins who are reared in separate environments. He notes that they usually exhibit similar adult behavior. He then wonders if there is really any such thing as freedom of the will, and if not, he ponders what to make of moral responsibility and punishment.


3.       A political science professor reads John Rawls’s A Theory of Justice and grapples with the idea that society’s primary goods could be distributed in such a way that those on the bottom get the maximum benefit even if people on the top have to be constrained. He wonders how this compares with a meritocracy wherein individual merit is rewarded regardless of social distribution. Several questions run through his mind: What is the state? How should a Christian view the state and the church? What is justice, and what principles of social ordering ought we adopt? Should one seek a Christian state or merely a just state?


4.      A neurophysiologist establishes specific correlations between certain brain functions and certain feelings of pain, and she puzzles over the question of whether or not there is a soul or mind distinct from the brain.


5.      An anthropologist notes that cultures frequently differ over basic moral principles and goes on to argue that this proves that there are no objectively true moral values that transcend culture.


6.      A businessman notices that the government is not adequately caring for the poor. He discusses with a friend the issue of whether or not businesses have corporate moral responsibilities or whether only individuals have moral responsibility.


7.      A mathematician teaches Euclidean geometry and some of its alternatives and goes on to ask the class if mathematics is a field that really conveys true knowledge about a subject matter or if it merely offers internally consistent formal languages expressible in symbols. If the former, then what is it that mathematics describes? Do numbers exist and, if so, what are they?


8.      An education major is asked to state his philosophy of education. In order to do this, he must state his views on human nature, the nature of truth, how people learn, what role values play in life, what the purpose of education ought to be and who should be entitled to an education.


9.      A physicist ponders Einstein’s theory about the relativity of space and time, and she believes that space and time themselves must be distinguished from the empirical, operational space and time utilized in scientific observations and tests. She agrees that the latter are relative, but she does not think that this settles the question of the real nature of actual space and time. Each example is a case where philosophy is relevant to some other discipline of study and crucial for the task of forming a well-reasoned, integrated Christian worldview. Philosophy asks normative questions (What ought one believe and why? What ought one do and why?), it deals with foundational issues (What is real? What is truth? What can humans know? What is right and wrong? Do right and wrong exist? What are the principles of good reasoning and evidence evaluation?), and it seeks knowledge of what some phenomenon must be in all possible worlds, not what may happen to be the case in this actual world. In each of the cases listed above, there is a need for the person in question, if he or she is a Christian, to think hard about the issue in light of the need for developing a Christian worldview. When one addresses problems like these, there will emerge a number of different ways that Christian doctrine and theology can interact with an issue in a discipline outside theology. And philosophy can be useful both in deciding which model is the best one to use in a specific case and in helping a person do the work of integration within that chosen model. Here are some of the different ways that such interaction can take place.


         1.      Propositions, theories or methodologies in theology and another discipline may involve two distinct, nonoverlapping areas of investigation. For example, debates about angels or the extent of the atonement have little to do with organic chemistry. Similarly, it is of little interest to theology whether a methane molecule has three or four hydrogen atoms in it.


         2.      Propositions, theories or methodologies in theology and another discipline may involve two different, complementary, noninteracting approaches to the same reality. Sociological aspects of church growth, certain psychological aspects of conversion may be sociological or psychological descriptions of certain phenomena that are complementary to a theological description of church growth or conversion.


         3.      Propositions, theories or methodologies in theology and another discipline may directly interact in such a way that either one area of study offers rational support for the other or one area of study raises rational difficulties for the other. For example, certain theological teachings about the existence of the soul raise rational problems for philosophical or scientific claims that deny the existence of the soul. The general theory of evolution raises various difficulties for certain ways of understanding the book of Genesis. Some have argued that the big bang theory tends to support the theological proposition that the universe had a beginning.


         4.      Theology tends to support the presuppositions of another discipline and vice versa. Some have argued that many of the presuppositions of a realist understanding of science (see chap. 16) (e.g., the existence of truth, the rational, orderly nature of reality, the adequacy of our sensory and cognitive faculties as tools suited for knowing the external world) make sense and are easy to justify given Christian theism, but are odd and without ultimate justification in a naturalistic worldview. Similarly, some have argued that philosophical critiques of epistemological skepticism and defenses of the existence of a real, theory-independent world and a correspondence theory of truth (according to which true propositions correspond with the “external” world; see chaps. 5-6) offer justification for some of the presuppositions of theology.


         5.      Theology fills out and adds details to general principles in another discipline and vice versa, and theology helps one practically apply principles in another discipline and vice versa. For example, theology teaches that fathers should not provoke their children to anger, and psychology can add important details about what this means by offering information about family systems, the nature and causes of anger, etc. Psychology can devise various tests for assessing whether one is or is not a mature person, and theology can offer a normative definition to psychology as to what a mature person is.


These are some of the ways that integration takes place. From the examples and models listed above, it should be clear that philosophy is central to the task of integration. Nevertheless, the task of forming an integrated worldview is a very difficult one, and there is no set of easy steps or principles that exhaustively describes how that task is to be conducted or what role philosophy should play in the quest for integration. With this in mind, the following is a list of principles that can aid someone unfamiliar with philosophy to think more clearly about its role in integration.


1. Philosophy can make clear that an issue thought to be a part of another discipline is really a philosophical issue. It often happens that scholars, untrained in philosophy, will discuss some issue in their field and without knowing it, cross over into philosophy. When this happens, the discussion may still be about the original discipline, but it is a philosophical discussion about that discipline.


         For example, attempts to put limits on a given discipline and attempts to draw a line of demarcation between one field of study and another, say between science and theology, are largely philosophical matters. This is because such attempts assume a vantage point outside of and above the discipline in question where one asks second-order questions about that discipline. Philosophy, it will be recalled, focuses on these kinds of second- order questions.

         Consider the following six propositions that describe conditions under which

         science places a limit on theology or vice versa:

         S1. Theological beliefs are reasonable only if science renders them so.

         S2. Theological beliefs are unreasonable if science renders them so.


S3. Theological beliefs are reasonable only if arrived at by something closely akin to scientific methodology.

         T1. Scientific beliefs are reasonable only if theology renders them so.

         T2. Scientific beliefs are unreasonable if theology renders them so.


T3. Scientific beliefs are reasonable only if arrived at by theologically appropriate methods.


Contrary to initial appearances, these propositions are not examples of science or theology directly placing limits on the other, for none is a statement of science or theology. Rather, all are philosophical statements about science and theology. Principles about science and theology are not the same as principles of science and theology. These six principles are philosophical attempts to limit science and theology and show their relationship.


Consider a second example of where a discussion crosses over into philosophy almost unnoticed.

         Evolutionist: The origin of life from inanimate matter is a well-established

         scientific fact.


Creationist: But if life arose in the oceans (abiogenesis) as you claim, then dilution factors would have kept the concentration of large, macromolecules to levels so small as to have been negligible.


Evolutionist: Well, so what? I do not think abiogenesis took place in the ocean anyway. Rather, it took place in some isolated pool that had some concentrating mechanism in place.


         Creationist: But the probabilities for such a process are incredibly small, and in any case, evidence appears to be coming in that the early earth’s atmo- sphere was a reducing atmosphere, in which case the relevant reactions could not occur.


Evolutionist: Give us more time, and we will solve these problems. The only alternative, creationism, is too fantastic to believe, and it involves religious concepts and is not science at all.


Creationist: Well, neither is evolution science. Science requires firsthand observation, and since no one was there to observe the origin of first life, any theory about that origin is not science, strictly speaking.

The discussion starts out as a scientific interaction about chemical reactions, probabilities, geological evidence and so on. But it slides over into a second-order philosophical discussion (one that represents a misunderstanding of the nature of both creationism and science; see chaps. 15-17), about what science is and how one should define it. These issues are surely relevant to the debate, but there is no guarantee that two disputants trained in some first-order scientific discipline have any expertise at all about the second-order questions of what science is and how it should be practiced. If scientists are going to interact on these issues, then philosophy will be an essential part of that interaction.


2. Philosophy undergirds other disciplines at a foundational level by providing clarity, justification for or arguments against the essential presuppositions of that discipline. Since philosophy operates as a second-order discipline that investigates other disciplines, and since philosophy examines broad, foundational, axiological, epistemological, logical and metaphysical issues in those other disciplines, then philosophy is properly suited to investigate the presuppositions of other disciplines. For example, in linguistic studies, issues are discussed regarding the existence, nature and knowability of meaning. These issues, as well as questions about whether and how language accomplishes reference to things in the world, are the main focus of the philosophy of language and epistemology.


Again, science assumes there is an external world that is orderly and knowable, that inductive inferences are legitimate, that the senses and mind are reliable, that truth exists and can be known, and so on. Orthodox theology assumes that religious language is cognitive, that knowledge is possible, that an intelligible sense can be given to the claim that something exists that is not located in space and time, that the correspondence theory of truth is the essential part of an overall theory of truth and that linguistic meaning is objective and knowable. These presuppositions, and a host of others besides, have all been challenged. The task of clarifying, defending or criticizing them is essentially a philosophical task.


3. Philosophy can aid a discipline by helping to clarify concepts, argument forms and other cognitive issues internal to a field. Sometimes the concepts in a discipline appear to be contradictory, vague, unclear or circularly defined. Philosophers who study a particular discipline can aid that discipline by bringing conceptual clarity to it. An example would be the wave-particle nature of electromagnetic radiation and the wave nature of matter. These concepts appear to be self-contradictory or vague, and attempts have been made to clarify them or to show different ways of understanding them.


Another example concerns some conceptions of the mechanisms involved in evolutionary theory. Some scientists have held that evolution promotes the survival of the fittest. But when asked what the “fittest” were, the answer is that the “fittest” were those that survived. This was a problem of circularity within evolutionary theory, and attempts have been made to redefine the notion of fitness and the goal of evolution (e.g., the selection of those organisms that are reproductively favorable) to avoid circularity. Whether or not these responses have been successful is not the point here. The point is,

rather, that philosophers have raised problems for a scientific theory because of issues of conceptual clarity. In these and other examples like them, philosophy can help to clarify issues within a discipline. When philosophy is brought to bear on questions of this sort, the result may be that the theory in question is problematic because it involves an internal contradiction or is somehow self-refuting.


For example, the sociological claim that there is no difference between intellectual history (roughly, the attempt to trace the development of ideas through history by focusing on the rational factors involved in the ideas themselves, including their own inner logic and relationships to ideas coming after them, e.g., the development of empiricism from John Locke to George Berkeley to David Hume) and the sociology of knowledge (the attempt to trace the development of ideas as a result of nonrational factors in a given culture, e.g., social status, economic conditions and so on) is sometimes justified by an appeal to conceptual relativism. The claim is made that different cultures have different language games, different views of the world and so forth, and that all of one’s views are determined by nonrational factors and thus are not to be trusted. Such a claim is self-refuting, for presumably this theory itself would be untrustworthy on its own terms.


4. Philosophy provides a common language or conceptual grid wherein two disciplines can be directly related to one another and integrated. Sometimes two different disciplines will use a term in a slightly different but not completely unrelated way. When this occurs, philosophy can help to clarify the relationship between the different disciplinary uses of the term in question.


For example, sometimes an operational definition of some notion can be related to an ordinary language definition of that notion or a definition from another field. An operational definition is, roughly, a definition of some concept totally in terms of certain laboratory or experimental operations or test scores. Thus one could operationally define a number of sociological concepts (minority group, traditional family roles, group leadership) or psychological terms (depression, intelligence) completely in terms of some operation or test score. A person could be said to be depressed if and only if that person scored between such and such a range on some standard psychological test.


Now these operational definitions may be related to our ordinary language notions of the relevant concepts in question; but they may not be clearly related, and in any case, they are certainly not identical to them. So philosophical clarity needs to be given before we can specify the relationship between depression as it is understood in ordinary language and depression as it is operationally defined in some test.


This type of philosophical elucidation is especially important when the term in question appears to be normative in nature. Thus, if one tries to give an operational, psychological definition of a “mature” or “healthy” adult, then all

one can give is a descriptive definition, not a prescriptive one, for psychology as it is currently practiced is a descriptive field. Philosophy focuses on moral prescriptions and oughts; psychology focuses on factual descriptions. So philosophy becomes relevant in clarifying the relationship between a “mature” adult, psychologically defined, and a “mature” adult taken as a normative notion (i.e., as something one ought to try to achieve).


Philosophy also helps to clarify and relate the different disciplinary descriptions of the same phenomenon. For example, biologists describe a human being as a member of the classification Homo sapiens. Philosophy, theology, law and political science (to name a few) treat a human being as a living entity called a human person. It is a philosophical question as to whether the two notions are identical and, if they are not, how they relate to one another.


5. Philosophy provides external conceptual problems for other disciplines to consider as part of the rational appraisal of theories in those disciplines (and vice versa). A philosophical external conceptual problem arises for some theory in a discipline outside of philosophy when that theory conflicts with a doctrine of some philosophical theory, provided that the philosophical theory and its component doctrines are rationally well founded. For example, suppose there were a good philosophical argument against the view that history has crossed an actual infinite number of events throughout the past to reach the present moment. If this argument is a reasonable one, then it tends to count against some scientific theory (e.g., an oscillating universe) which postulates that the past was beginningless and actually infinite. If there were a good philosophical argument for the claim that space and time are absolute, then this argument would tend to count against scientific theories to the contrary.


Again, if there are good philosophical arguments for the existence of genuine freedom of the will or arguments for the existence of real moral responsibility and the necessity of full-blown freedom as a presupposition of moral responsibility, then these would tend to count against sociological, economic or psychological theories that are deterministic in nature. In cases like these, a rationally defensible position is present within philosophy, and it runs contrary to a theory surfaced in another field. The philosophical external conceptual problem may not be sufficient to require abandonment or suspension of judgment of the theory in the other discipline; it may merely tend to count against it. Even so, these kinds of conceptual problems show that philosophical considerations are relevant to the rationality of theory-assessment in other disciplines.


In sum, we have looked at five different ways that philosophy enters into the task of integration in a Christian university. It is important to realize that the Christian philosopher should adopt the attitude of faith seeking understanding. The Christian philosopher will try to undergird, defend and clarify the various aspects of a worldview compatible with Scripture. This will involve working not only on broad theological themes—for example, the dignity of being human—but on defending and clarifying specific verses in Scripture. Of course, caution must be exercised. One should not automatically assume that one’s particular interpretation of a biblical text is the only option for an evangelical, and one should not automatically assume that the biblical text was intended to speak to the issue at hand. But when due care is given to these warnings, it is nevertheless important that the Christian philosopher tries to forge a worldview that includes the teaching of specific biblical texts, properly interpreted.


Earlier in the chapter reference was made to a remark from Saint Augustine to the effect that the Christian intellectual must work on behalf of the church to show that Scripture does not conflict with any rationally justified belief from some other discipline. Over seventy-five years ago the great evangelical Presbyterian scholar J. Gresham Machen remarked that false ideas were the greatest hindrance to the gospel. According to Machen, we can preach with all the fervor of a reformer and even win a straggler here and there; but if we permit the whole collective thought of the nation or world to be dominated by ideas that, by their very logic, prevent Christianity from being regarded as anything more than a hopeless delusion, then we do damage to our religion.


Members of the Christian family have a responsibility to promote worldwide evangelization, the nurture of the saints and the penetration of culture with a Christian worldview. This task is important to the very life and health of the church, and when we engage in it, philosophy is now, as it has always been, an essential participant in this great task.


While there is no airtight definition for philosophy, nevertheless, three features of philosophy help us understand what it is. The term philosophy means love of wisdom, and philosophy is an attempt to think rationally and critically about life’s most important questions. Moreover, philosophy is a second-order discipline. Finally, there are several first-order areas of philosophy itself, such as logic, metaphysics, epistemology and value theory.

From a Christian perspective, philosophy can be an aid to apologetics, polemics and systematic theology. Further, work in philosophy can be a central expression of the image of God and can be a spiritual discipline. Finally, philosophy can help to extend biblical teaching to areas not explicitly mentioned in Scripture, it can enhance the self-image of the believing community, and it can aid in the task of integrating theology with other disciplines in forming a Christian worldview. Moreover, four arguments against philosophy were evaluated and rejected. The last section of the chapter cited examples of the need for integration and for philosophy to be involved in that activity, various models of integration were listed, and five philosophical principles used in integration were examined.




external conceptual problem


first-order discipline


intellectual history



noetic effects of sin

operational definition



second-order discipline

sociology of knowledge

value theory




1.      Augustine On the Literal Interpretation of Genesis 1.21.


2.      John G. Gager, Kingdom and Community: The Social World of Early Christianity (Englewood Cliffs, N.J.: Prentice-Hall, 1975), pp. 86-87.


3.      C. S. Lewis, The Weight of Glory (Grand Rapids, Mich.: Eerdmans, 1949), p. 50.


4.      William Wilberforce, Real Christianity (Portland, Ore.: Multnomah Press, 1982; based on the 1829 edition), pp. 1-2.

About the Authors:

J.P. Moreland (Ph.D., University of Southern California) is Distinguished Professor of Philosophy at Talbot School of Theology, Biola University, in La Mirada, California. He has written, edited or contributed to twenty books with publishers ranging from Oxford University Press, Routledge, Wadsworth and Prometheus to Zondervan and InterVarsity Press. Among his books are Christianity and the Nature of Science, Does God Exist? (with Kai Nielsen) and Philosophical Naturalism: A Critical Analysis. He has also published more than fifty articles in journals such as Philosophy and Phenomenological Research, American Philosophical Quarterly, Australasian Journal of Philosophy, MetaPhilosophy, Pacific Philosophical Quarterly, Southern Journal of Philosophy, Religious Studies and Faith and Philosophy. He is a fellow of the Discovery Institute's Center for the Renewal of Science and Culture.

William Lane Craig (Ph.D., philosophy, University of Birmingham; D.T., systematic theology, University of Munich) is Research Professor of Philosophy at Talbot School of Theology, Biola University, in La Mirada, California. He has published articles in philosophical and theological journals such as The Journal of Philosophy, American Philosophical Quarterly, Philosophical Studies, Philosophy, British Journal for the Philosophy of Science, Modern Theology and Religious Studies. He has written or co written more than twenty books, including The Kalam Cosmological Argument; Divine Foreknowledge and Human Freedom; Theism, Atheism and Big Bang Cosmology and God, Time and Eternity.

Taken from Philosophical Foundations For A Christian Worldview by J.P. Moreland and William Lane Craig. Copyright © 2003 by J.P. Moreland and William Lane Craig. Permission kindly granted to Faith & Reason Forum by InterVarsity Press.