Karl Popper and The Philosophy of Science

The Bobgans Misrepresent Crabb

The Bobgans Misunderstand Popper

A Valuable Lesson: Believers Can Learn From Unbelievers

Unbelievers are Captives to God’s Creation

Truth and Falsehood in Secular Psychology, According to Cornelius Van Til

The Bobgans Do Not Understand the Real Issue

More on Karl Popper: Without Revelation, he is Wrong


The Bobgans Misrepresent Crabb

The Bobgans appeal to Karl Popper in chapter 11 of Prophets of Psychoheresy I, a chapter that attempts to discuss Dr Crabb’s doctrine of the unconscious. 1 Popper’s name appears there in a section entitled “The Unconscious: Scientific Fact or Fiction?”, which begins with a doubly questionable assertion:

Crabb speaks of his Freudian-based theory of the unconscious as though it were a scientifically established fact. 2

In the first place, it is not true that Crabb’s theory is “Freudian-based.” (The Bobgans believe they established that point back in chapter 9, but their argument there fails. However, the material I want to cover right now about Karl Popper will make it easier to understand what is wrong in chapter 9, so we will return to that issue later). And, secondly, Crabb does not speak of his theory as though it were a scientifically established fact. Rather, he speaks of it as based on the Bible; he does not make the claim that the Bobgans say he does. On the contrary, in his very first book Basic Principles of Biblical Counselling he says:

Nowhere is the proliferation of differing, untestable notions more appallingly evident than in the psychologists’ offices. 3


….the scientific research method is inherently inadequate for the job of defining truth. Science can provide neither proof nor meaning… modern philosophers of science confess the incurable impotency of science to ever say anything conclusively. 4

However, the Bobgans seem to have overlooked this, and so, believing they are refuting Crabb, they quote Sir Karl Popper in support of their own statement that,

No one has ever proven that the Freudian unconscious exists. Nor has anyone scientifically verified the contents of the unconscious. 5

The Bobgans Misunderstand Popper

These words of the Bobgans show two things: (1) they accept Karl Popper as an authority on what is and isn’t scientific, and (2) they do not understand Karl Popper.

The first point is evident just from reading the Bobgans’ own words; the second needs explanation. The question that was the concern of Karl Popper in his great work The Logic of Scientific Discovery6 is, “What marks a theory as scientific? Why are some theories worthy of that name, and others not?” 7

His answer was radical. He contended that a theory can only be considered scientific if it makes predictions of events which, if they do not occur, will show that the theory is false. Before Popper, people had tended to think that a theory was scientific because it had been verified – that is, a scientist had proposed a theory, then conducted an experiment based on the theory, and the experiment had turned out as predicted. People clung to that view of science even though as early as the 1700’s the philosopher David Hume has shown that no theory ever could be said to be proven true by one successful experiment, or a hundred, or a million. 8

No, as Popper says, “Theories are … never empirically verifiable.” 9 Instead, “A theory that is not refutable by any conceivable event is nonscientific. Irrefutability is not a virtue of a theory (as people often think) but a vice.” 10

The reason that Popper says that psychiatric theories are not scientific is that (he believes) they are not falsifiable. However, the Bobgans use him to support their statement that no one has scientifically verified the contents of the unconscious. Reading the Bobgans, you would be led to believe that Popper thought that there were some theories that had been scientifically verified, though psychiatry was not one of them. However, according to Popper, no theory has ever been scientifically verified – not even Newton’s laws, or Einstein’s.

A Valuable Lesson: Believers Can Learn From Unbelievers

So, then, we find the Bobgans making muddled use of Karl Popper to prove Larry Crabb wrong in saying something he didn’t say and doesn’t believe. However, there is a useful lesson to be learned from the way that the Bobgans appeal to Karl Popper in support of their case.

First, Popper’s philosophy is adamantly anti-biblical, yet the Bobgans have valued some of his words so highly that they use them in a book in defence (so they imagine) of a part of the Christian faith. The anti-biblical roots of his thinking can be seen in a statement early in Logic of Scientific Discovery:

…epistemology… should be identified with the theory of the scientific method. 11

Now, epistemology is the study of how we know what we know (and whether we know anything at all for sure). For a Christian, knowledge is based first and foremost on God’s revelation; but for Popper, epistemology and the theory of scientific method are one and the same thing. There is no room for revelation in his system, which takes for granted Satan’s lie human beings are able to be “like God, knowing good and evil.” (Genesis 3:5).

The Bobgans say of Crabb’s willingness to learn from secular psychologists,

It is amazing that Christians choose to drink from such antichristian psychological belief systems. 12

If that criticism were justified, we could with equal force say of the Bobgans in their use of Popper, “It is amazing that Christians choose to drink from such antichristian epistemological belief systems.” However, as I will explain further, the Bobgans are not wrong to make discerning use of Popper, just as Crabb is not wrong to make discerning, biblically-informed use of Freud.

Second, Popper does not have the field to himself. There are competing philosophers of science and some of them disagree strongly with Popper. Another science philosopher, Alan Chalmers, describes the situation like this:

I found, to my surprise, that there were philosophers influenced by Wittgenstein or Quine or Marx who thought that Popper was quite wrong on many issues, and some who even thought that his views were positively dangerous. I think I have learnt much from that experience. One of the things that I have learnt is that on a number of minor issues Popper is indeed wrong, …. however, this does not alter the fact that the Popperian approach is infinitely better than the approach adopted in most philosophy departments that I have encountered. 13

I agree with Chalmers that Popper despite his flaws, comes much nearer the truth than those who put forward thoroughly different theories about the scientific method. Evidently the Bobgans agree too. They must therefore agree that it is possible for a Christian to look at various non-Christian theoretical systems and discern that one is nearer the truth than the other. And they must also agree that it is possible for a Christian to discern where the non-Christian systems most nearly approach the truth, and where they are furthest from it.

Their own example shows that the Bobgans have no grounds for finding fault with Crabb for his willingness to read and learn from secular sources. Though they might choose to disagree with him on details, they have no grounds to complain about the method itself.

Unbelievers are Captives to God’s Creation

The Bobgans are inconsistent when they criticise Crabb. However, someone might say, “Indeed, they are inconsistent, but the solution is for them to repent and give up their appeal to Popper, not for them to abandon their criticism of Crabb.” Therefore we must now consider just why it is that a person whose motives are antichristian can nevertheless discover and publish what – in Christian hands – is true and right and good.

Cornelius Van Til14 has many times pointed out that though the non-Christian hates God and always reasons from presuppositions that deny God, as a matter of fact he is God’s creature and lives in a world created by God. If he is to live at all successfully, he must live as though Christianity is true. He builds his physical house from bricks created by God, even though on his non-Christian presuppositions he cannot so much as prove that the bricks exist or that the laws of physics which up until now have enabled houses to be built and hold together will still be true tomorrow. Likewise, he must build his intellectual house from materials provided by God. All that the unbeliever builds he builds with the goal of proving that he is god, and God is not. Nevertheless, if his system of thought is to have any practical connection with the world in which the unbeliever actually lives – a world created and controlled by God – it must in many key respects tell the truth about that world. 15

In Van Til’s words,

…because man is a creature of God, it is impossible that he should ever be alienated from God metaphysically. He can never actually become the independent being he thinks he is. Even the King’s heart is in the hand of God as the watercourses. 16


…as a sinner, man seeks to make himself, instead of God, the ultimate aim as well as the ultimate standard in life. Yet he cannot ultimately change the practical situation. He is still a creature. The universe is still what God has made it to be, and it will be what God intends it to be. So fallen man cannot destroy the programme of God. He cannot even destroy himself as inherently a builder of culture for God. In spite of what he does against God, he yet can and must work for God; thus he is able to make a “positive contribution” to human culture. Thus it comes to pass that they of whom scripture says that their minds are darkened can yet discover much truth. 17


….since sinners are not consistent … they can engage in science and in the general interpretation of the created universe and bring to light much truth. It is because the prodigal is not yet at the swine trough and therefore still has of the substance of the Father in his pockets that he can do that and discover that, which for the matter of it, is true and usable for the Christian. 18

There is no need, therefore, to view with horror (as the Bobgans do) everything that comes from the pen of a non-Christian psychologist, and to expect that nothing true will be found there. 19 In fact, to have the Bobgans’ attitude is to concede to the non-Christian mind a power of creativity – independent of God – which the Bible testifies it does not have.

Truth and Falsehood in Secular Psychology, According to Cornelius Van Til

In his syllabus Psychology of Religion, Van Til traces the steps by which secular psychology this century has deepened its rebellion against God, but as he does so he also identifies insights in it which are true, or would be true if turned to godly purposes in Christian hands. 20 If we follow what he says there, we can see illustrated just what he means about the way non-Christian thought can be true in its substance, even while it is false in its motives.

In step 1, “…the intellect lost its place of high authority. This might have been done in the interest of a Christian type of thought. Christianity has always sought to equalize all the aspects of man’s personality. However the dethroning of the intellect was not done in the interest of Christian theism but in the interest of Irrationalism.”

In step 2, “…the new psychology reacted against the separation of the soul from the body. This too might have been in the interest of Christian theism. ….The Christian position has never been guilty of abstract separation of the soul and the body. Accordingly, insofar as the new psychology seeks to bring soul and body into close harmony with one another, we can only rejoice. However, we should again observe that this bringing of soul and body together by modern psychology is in the interest of wiping out the distinction between them.”

In step 3, “…the new psychology reacted against the old in that it laid more emphasis upon child psychology…. With respect to this third step we observe again that it too might have been taken in the interest of Christian theism. Individuality is a concept that is embedded in the very foundations of theism. As Christianity does justice to the emotional and volitional, so it also does justice to the individuality of each person….” [but] “…modern psychology thinks of personality as being exclusively a self-accomplishment on the part of man. At this point it is directly opposed to Christianity which holds that personality is created by God.”

Step 4 was the emphasis on the unconscious, and Van Til says, “Even this fourth step of modern psychology has ‘good elements’ in it… [We] … also believe that man was part conscious and in part unconscious in his activity… Scripture is full of the idea of the subconscious. David prays that he may be forgiven for sins of which he is unaware. We say that we are born and conceived in sin which does not merely refer to the activity of the parents but means that we are sinners when we come into the world even though we are not self-conscious.”

Step 5 is the study of abnormal psychology. Van Til’s comment is, “The study of abnormal psychology is a good thing. It has undoubtedly thrown light not only on the behaviour of the abnormal but also on the behaviour of the normal…. It is not the fact that men turned to the study of the abnormal psychology that is important, but the reason why they did it. This reason was the assumption that the normal and the abnormal are both normal in the sense that they are both naturally to be expected in human life.”

Even the sixth step, the study of the soul of “primitive man,” has its Christian correlation. Only the seventh step (the elevation of the animal as a principle of explanation for man) has no element of truth in it.

The Bobgans Do Not Understand the Real Issue

Near the conclusion of a book whose subject is biblical psychology, Rousas Rushdoony (who well understands Van Til) observes,

This does not mean that some interesting things have not been discovered by psychologists, psychoanalysts, and psychiatrists. To recognize an enemy as an enemy does not mean we cannot learn from him, but we must at all times be aware of the framework of his ideas and discoveries. 21 , 22

On the last page of the same book he says:

If the Bible is right, mental health is a product of justification, of the atonement effected by Jesus Christ, applied and developed in the life of man… Man cannot find mental health apart from faith and obedience. 23 , 24

What if Larry Crabb’s doctrines of psychology and counselling are in fact built upon that kind of foundation? What if the kind of use he makes of Freud and Adler and Jung is precisely and only the kind of use that Van Til says a Christian should be able to make of them? I believe that is just about what Crabb has achieved, though there is undoubtedly room for further development and correction. However, the Bobgans give no evidence that they understand that these questions exist to be asked, let alone what their answers are.

More on Karl Popper: Without Revelation, he is Wrong

We have reached this point as a result of a discussion of Karl Popper’s doctrine of the scientific method: a discussion which led in turn to a consideration of what Cornelius Van Til had to say about the validity of non-Christian research. There is one more topic that needs to be touched upon before we leave Popper behind.

Popper’s doctrine is not the final word. Apart from the hostile criticism that Popper received from the philosophers whom Alan Chalmers mentions, even Popper’s disciple Imre Lakatos recognised problems with Popper’s doctrine. He attempted to correct them, but there are problems with his theory, too, which Alan Chalmers in his turn has attempted to correct. 25 And Chalmers also fails, I believe. All of these men – Popper, Lakatos, Chalmers – fall foul of a problem that Van Til shows is generic to all non-Christian thought:

The result for man was that he made for himself a false idea of knowledge. Man made for himself the ideal of absolute comprehension in knowledge. This he could never have done if he continued to recognize that he was a creature. It is totally inconsistent with the idea of creatureliness that man should strive for comprehensive knowledge; if it could be attained, it would wipe God out of existence; man would then be God. And, as we shall see later, because man sought for this unattainable ideal, he brought upon himself no end of woe. 26

Popper’s basic idea remains a good one. After all, why do we want to know which theories to call “scientific”? Surely it is so we can know which ones are most likely to help us make our way successfully through this world. It seems right, therefore, when Popper says that such a theory will be one that is falsifiable. What Lakatos and Chalmers have shown, though, is that it is impossible, if you start with secular presuppositions, to come up with a definition of “falsifiable” that actually works in the world of science as it is actually practised. 27

What this means is that you cannot even arrive at a practical definition of what is scientific unless you start with God’s revelation of Himself to us His creatures. The Bobgans wrongly accuse Crabb of going to a court of appeal outside the Scriptures for justification for his psychological doctrines. He does not – but the Bobgans set up just such a court of appeal in support of their own doctrine of the scientific method. Their court of appeal is Karl Popper, and Popper is wrong.

Where that takes us, is that Popper’s judgement about what is and isn’t scientific is not reliable. Biblical thinking has to be brought to bear to make a sound judgement on any such question. Therefore, in conclusion to this section we can observe:

(1) Contrary to Popper, psychological theories are not necessarily unscientific;

(2) Contrary to the Bobgans, even the most rabidly non-Christian presuppositions do not mean that secular theories contain no insights that are of value to Christians;

(3) Crabb begins with the scriptures, not secular psychology. However, his understanding of what the scriptures are saying is honed and deepened by psychologists’ published observations and theories of patterns of human behaviour, and ( cf. Van Til) there is nothing unbiblical about his doing just that

(4) Even in the days when law was explicitly Christian, judges did not go solely to the scriptures when deciding a case. They also went to records of other similar cases, for help in thinking through the issues. They went outside the scriptures, but that did not in the least bit reduce their practical commitment to them. In a similar way, a Christian counsellor can go to extra-biblical material for assistance without compromising his stand on the scriptures themselves.


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1 They also quote Popper in their earlier book Psychoheresy, chapter 3. 2 Bobgan (1989) p. 151 3 Crabb (1975) p. 21
4 Crabb (1975) p. 22 5 Bobgan (1989) p. 151 6 Popper (1959)
7 cf. Popper( 1963) p. 33. 8 I will not explain why here. For an excellent overview of the history of the philosophy of science, read Chalmers (1976). 9 Popper (1959) p. 6 (emphasis his).
10 Popper, Scientific Theory and Falsifiability. (Quoted in Bobgan (1989) p. 152).
11 Popper (1959) p. 49 12 Bobgan (1989) p. 133 13 Chalmers (1976) p. xii
14 Cornelius Van Til was for many years Professor of Apologetics in Westminster Theological Seminary, Philadelphia.
15 Francis Schaeffer somewhere illustrates this by pointing out that the director of a modern film may have his characters enter and leave through the window rather than the door. The director does this to demonstrate mankind’s supposed freedom from the old, Christian absolutes. Nevertheless, it is still through windows that the actors pass, not through the walls. The director’s ethical rebellion against God is total, but his practical rebellion is limited by the reality of the fact that this is, after all, God’s world. (In a fantasy film, the special effects people would have no difficulty creating the illusion of someone passing through a wall, but the kind of film Schaeffer speaks of is intended to make a serious philosophic statement about real people in a real world; a fantasy film is not).
16 Van Til (1969/III) p. 197 17 Van Til (1969/I) p. 44 18 Van Til (1969/I) p. 294
19 The Bobgans think I have misrepresented them here because early in Prophets of Psychoheresy I (pp. 4-5) they indicate a willingness to learn from some parts of the discipline of psychology. However, this essay concerns the area of psychological counselling. In this area the Bobgans are not willing to allow that secular psychologists have any insight, whereas Van Til’s words (quoted further below) show that he expected to be able to learn from secular thinkers even there.
20 Van Til (1969/II) pp. 66-79, “General Psychology and the Psychology of Religion”.
21 Rushdoony (1977) p. 328.
22 Rushdoony also says a few pages later (p. 336):

“…the popular psychology of our time has no rightful place in the church, in that it is implicitly anti-theological and man-centred rather than God-centred. For pastors to borrow from contemporary humanistic theologies means to introduce an alien doctrine of salvation to their congregations.”

Torn from the full context of Rushdoony’s writings, this would not sound out of place in one of the Bobgans’ books, and, indeed, they quote other material from him in Psychoheresy, (pp. 157f). However, Rushdoony’s words show that – unlike the Bobgans – he understands the breadth of the issues involved.

23 Rushdoony (1977) p. 336
24 The ellipsis in the quote indicates a place where I have omitted a sentence, which, if I included it, might give the impression that Crabb, like Rushdoony, is a theonomist. He is not, but neither does he equivocate about the need for us to obey the clear precepts of God’s Word.
25 Chalmers (1976)

26 Van Til (1980) p. 15

27 They, of course, do not discuss secular versus biblical presuppositions I am making my own assertion here about what their work means.

© 2009, Matt. All rights reserved.