In our last article, we looked at the concept of worldview-incommensurability, broadly speaking, with an emphasis on the incommensurability theories. In this article, we will look at this particular epistemological approach to knowledge in general, and science in particular, from more of a structural perspective. Philosophers of science and epistemologists who take a more holistic approach to knowledge, science and truth are understood as advocating 'coherentist' models of epistemology. It is important to understand the differences between the coherence theory of truth and the coherence theory of justification. The coherence theory of truth is opposed to the correspondence theory of truth, whereas the coherence theory of justification is opposed to the foundationalist theory of justification. Those who support the coherence theory of truth argue that what makes something 'true' is coherence within a system of thought rather than correspondence to an external reality. This is what we will discuss first.
For the advocate of the coherence theory of truth, a proposition is true insofar as it "consists in its coherence with some specified set of proposition"(Young 2013). For the coherentist, the relation which truth bears to a proposition is coherence (consistency within a set of propositions) rather than correspondence (isomorphism with some external object). Both theories of truth, however, are opposed to deflationary conceptions of truth (Young 2013). This means that "coherence and correspondence theories both hold that truth is a property of propositions that can be analysed in terms of the sorts of truth-conditions propositions have, and the relations propositions stand in to these conditions" (Young 2013).
Young notes that there are numerous distinct forms of the coherence theory of truth. "The coherence theory of truth has several versions. These versions differ on two major issues. Different versions of the theory give different accounts of the coherence relation. Different varieties of the theory also give various accounts of the set (or sets) of propositions with which true propositions cohere. (Such a set will be called a specified set.)"(Young 2013). Some advocates of the coherence relation see coherence as mere consistency, such that "a proposition coheres with a specified say of propositions...[if it is] consistent with that set"(Young 2013). Young rejects such an account as inadequate because he notes that if we have two propositions that are not members of a specific set, then such propositions may be "consistent with a specified set and yet be inconsistent with each other. If coherence is consistency, the coherence theorist would have to claim that both propositions are true, but this is impossible"(Young 2013).
It ought to be noted that, despite their important differences, the presuppositionalists Cornelius Van Til, as well as Gordon Clark, both held to a form of the coherence theory of truth with respect to the mind of God. So Van Til:
"In opposition ot the historical correspondence theory of truth there arose in the Kant-Hegel tradition the so-called Coherence Theory of Truth...They said that true knowledge cannot be obtained by mere correspondence of an idea of the mind to all object existing apart from the mind. The mind and the object of which it seeks knowledge are parts of one great system of reality and one must have knowledge of the whole of this reality before one has knowledge of any of its parts. Accordingly, the Idealists said that the thing that really counted in knowledge was the coherence of any fact with all other facts. To know the place of a fact in the universe as a whole is to have true knowledge. This position, as we shall see more fully later, approachces, in form, what we are after in our position. Yet it is only in form that it approaches our position. That this is true can be seen from the determining fact that the Absolute tow hich the Idealist seeks to relate all knowledge is not the ceompletely self-conscious God of Christianity. We cannot prove this point here. We only state it as our conviction here in order to clear the ground. The Absolute of Idealism, we believe, is not really an absolute because he exists as merely correlative to the space-time world. Accordingly there are new facts arising for him as well as for us. God becomes a primus inter pares, a One among others. He can no longer be the standard of human knowledge.
It is our contention that only the Christian can obtain real coherence in his thinking. If all of our thoughts about the facts of the universe are correspondence with God's ideas of these facts, there will naturally be coherence in our thinking because there is a complete coherence in God's thinking. On the other hand we hold that the Idealistic coherence theory of truth cannot lead to coherence because it omits the source of all coherence, namely, God.
In a way it might be well for us to call our position the Coherence Theory of Truth because we claim to have true coherence. Whether we call our position a correspondence theory or whether we call it a coherence theory, we have in each case to distinguish it sharply from the theories that have historically gone by these names. Accordingly, the determining factor must be a consideration of that which is most fundamental in our theory of correspondence or of coherence. Now this depends upon the question whether we have God's knowledge in mind first of all, or whether we begin with human knowledge. For God, coherence is the term that comes first. There was coherence in God's plan before there was any space-time fact ot which his knowledge might correspond, or which might correspond to his knowledge. On the other hand, when when we think of human knowledge, correspondence is of primary importance. If there is to be true coherence in our knowledge there must be correspodnence between our ideas of facts nad God's ideas of these facts. Or rather we should say that our ideas must correspond to God's ideas. Now since we are dealing with opponentswho speak of human knowledge almost exclusively, we can perhaps best bring out the distinctiveness of our position by calling it thte Correspondence Theory of Truth. An additional reason for this choice is that at the present time the old correspondence t heory has pretty well died down, leaving the coherence theory in control of the field. Hence we have the advantage of a different name from the current name, since we are interested in making it clear that we really have a different theory from the current theory"(Van Til, A Survey of Christian Epistemology")
So also Gordon Clark:
"One who believes in the unity of truth may still believe that the false system entails contradictions; but to prove this is the work of omniscience." (Historiography: Secular and Religious, 1971, pg. 370)
Undoubtedly I hold that truth is a consistent system of propositions. Most people would be willing to admit that two truths cannot be contradictories; and I would like to add that the complex of all truths cannot be a mere aggregate of unrelated assertions. Since God is rational, I do not see how any item of his knowledge can be unrelated to the rest. Weaver makes no comment on this fundamental characteristic of divine truth.
Rather, he questions whether this characteristic is of practical value, and whether it must be supplemented in some way. It is most strange that Weaver here says, “I must agree with Carnell,” as if he had convicted me of disagreeing with Carnell by providing no supplementation whatever. Now, I may disagree with the last named gentleman on many points, but since it is abundantly clear that I “supplement” consistency by an appeal to the Scripture for the determination of particular truths, it is most strange that Weaver ignores my supplementation. (Clark and His Critics, 2009, pg. 290)
Both thinkers believed that a proposition possessed 'truth' insofar as it cohered with the other propositions in God's mind. In this respect, Young's criticism is off the mark, since God is omniscient, and so all propositions are members of the set of 'God's thoughts.' It ought to be noted that we use 'propositions' only in a loose, non-technical sense here, so far as Van Til is concerned, since he makes it clear in his "complaint" against Gordon Clark in the OPC's Clark/Van Til controversy that he does not, strictly speaking, believe that God's thoughts are proposition.
Van Til's emphasis thus seems to be on the internal consistency of God's mind, whereas Clark seems to emphasize logical entailment among each proposition. This is another popular understanding of what it means for coherence (and therefore truth) to obtain among propositions in a given set. Another version, Young notes, is that held by the British Idealist F.H. Bradley, according to which "coherence is mutual explanatory support between propositions"(Young 2013).
The other issue on which coherentists differ concerns "who believes the propositions [of a specified set] and when"(Young 2013). Some argue that "the specified set of propositions is the largest consistent set of propositions currently believed by actual people"(Young 2013). Others argue that "the specified set consists of those propositions which will be believed when people like us (with finite cognitive capacities) have reached some limit of inquiry"(Young 2013). Hilary Putnam's coherentism is an example of this. Finally, idealists and presuppositionalists both accept the position that "the specified set contains the propositions which would be believed by an omniscient being. Some idealists seem to accept this account of the specified set"(Young 2013). As we have seen before in both Clark and Van Til, this is precisely the historic presuppositionalist approach, and it is something which Clark and Van Til agree upon. Indeed, the original coherentists were idealists who accepted coherentism precisely on metaphysical grounds. Consider the following important difference between coherence theories of truth which are dependent upon the metaphysical notion that the specified set of coherent propositions are those in the mind of God, and those that conceive of propositional coherence as "the specified set...actually believed, or even a set which would be believed by people like us at some limit of inquiry"(Young 2013):
If the specified set is a set actually believed, or even a set which would be believed by people like us at some limit of inquiry, coherentism involves the rejection of realism about truth. Realism about truth involves acceptance of the principle of bivalence (according to which every proposition is either true or false) and the principle of transcendence (which says that a proposition may be true even though it cannot be known to be true). Coherentists who do not believe that the specified set is the set of propositions believed by an omniscient being are committed to rejection of the principle of bivalence since it is not the case that for every proposition either it or a contrary proposition coheres with the specified set. They reject the principle of transcendence since, if a proposition coheres with a set of beliefs, it can be known to cohere with the set (Young 2013).
Thus, the reason one holds to a coherence theory of truth has crucial implications for other elements of one's epistemology. The presuppositionalism held by Clarkians and Van Tillians is quite different from the coherentism held by later thinkers, whose reason for holding to coherentism was quite different. This difference ends up making quite a difference. It is this crucial difference which will be our object of inquiry after we have finished looking at the metaphysical justification for the position held by the idealists.
"Early versions of the coherence theory were associated with idealism. Walker (1989) attributes coherentism to Spinoza, Kant, Fichte and Hegel. Certainly a coherence theory was adopted by a number of British Idealists in the last years of the nineteenth century and the first decades of the twentieth. See, for example, F.H. Bradley (1914)"(Young 2013)
Let us lay the ground of the distinction between advocates of the correspondence theory of truth and the coherence theory. The former
"believe that a belief is...ontologically distinct from the objective conditions which make the belief true. Idealists do not believe that there is an ontological distinction between beliefs and what makes beliefs true. From the idealists' perspective, reality is something like a collection of beliefs. Consequently, a belief cannot be true because it corresponds to something which si not a belief. Instead, the truth of a belief can only consist in its coherence with other beliefs. A coherence theory of truth which results from idealism usually leads to the view that truth comes in degrees. A belief is true to the degree that it coheres with other beliefs"(Young 2013)
To summarize: For the idealist, reality consists merely in ideas. Van Til and Clark are both oftentimes associated with some form of idealism, though whether or not or the extent to which this is or can be justified is controversial. Let's take a look at David Hoover's "Gordon Clark's Extraordinary View of Men and Things," in which he argues that Clark was indeed a kind of idealist.
Indeed, David Hoover identifies Clark, in no uncertain terms, as an idealist. That is, the only sorts of things that exist are ideas in the mind of God. Clark was also, as we have seen, an advocate of the coherence theory of truth with respect to the mind of God. That is, all reality consists of ideas in the mind of God; reality consists precisely of the specified set of an exhaustive number of propositions in the mind of an omniscient, eternal and immutable God, and the truth-condition of these propositions is their coherence relative to other propositions in this specified set.
Though a presuppositionalist, Gordon Clark's epistemology differed radically from that of Cornelius Van Til, the other major heir of the name 'presuppositionalist.' Clark was radically imposed to empirical epistemologies for numerous reasons. Because he held that only those truths deduced logically from the Bible could constitute knowledge, he denied that inductive logic, a formally invalid form of reasoning, could ever produce knowledge. His reason for this is the classic problem of induction, according to which no amount of observed instances of an occurrence can produce knowledge, since our universal conclusions based on these observations may always be contradicted by a later occurrence. Furthermore, Clark rejects the ability of sensation to produce knowledge on the grounds that we have no criteria by which to distinguish a true perception from a false one.
For Clark, knowledge acquisition only occurs through deduction from an axiom, and for the Christian, that axiom is the Bible. Clark is therefore, with respect to the rationalist/empiricist debate, a stark rationalist. One can form opinion, even perhaps very reliable opinion, with the assistance of the senses, but true knowledge only comes through deducing theorems from the axiom of the Bible.
Less often discussed then Clark's epistemology itself, perhaps, is the metaphysical ground of his epistemology. Hoover points out that Clark believes that the only sorts of things that are knowable are propositions. All knowledge is propositional knowledge. Negatively, Clark's epistemology is opposed to the sort of representationalism to which empiricism is oftentimes committed. For example, most empiricists believe that the ideas in our minds are representations of an external object. This means that we can never know if our minds are accurately representing the external object. Indeed, this is precisely one of the reasons Clark rejects empiricism: we can never know if our representational ideas are accurate representations of their external realities, or indeed, whether or not such things even exist. They may simply be illusions. Clark therefore rejects representationalism as untenable. Note Hoover's contrast of Clark's positive epistemology with his anti-representationalism:
"It is crucial to take hold of the importance Clark attaches to the known object being in the mind which knows it. Suppose I claim to know that there are trees overarching my trailer. Clark would insist that if I did know this I could not know it representationally for the reason just quoted. But how then? I would have to know the reality itself-—viz., the reality of the very trees overarching my trailer. This reality itself would have to be in my mind and not any mere representation of it. Of course it is doubtful, to say the least, that I should know anything of this sort given Clark’s severe restriction on the scope of human knowledge. The trees in question are neither mentioned in, nor entailed by, Clark’s Axiom. But if this or any other piece of knowledge were to be in my mind it would follow that the nature of an object of knowledge would have to be mental"(Hoover)
Next, Hoover articulates the metaphysical upshot of such an epistemological position:
:Now note the above progression of thought. Without breaking philosophical stride, we’ve moved from epistemology to a fundamental metaphysical pronouncement. Clark’s epistemology entails Idealism. Thus from theory of knowledge Clark has begun to make good on his “different metaphysics,” his “different view of what reality consists of,” and his “different view of how one reality is related to another.”
Second, since all reality has been created by God, reality is thoroughly known by Him. But as we have just seen, to be known an object must be in the mind and hence mental in nature. But if all reality is known by God, reality is exhaustively mental in its nature; there is no room for any mind-independent objects at all and so Clark’s Idealism is thoroughgoing. There exists nothing that is not mental in its being.
Third, the character of the mentality of all things follows rigidly from the character of the items that are known. Knowledge is always knowledge of the truth and truth, in Clark’s view, is a quality of only propositions—that is, only propositions are the sort of thing that can be true (or false). Hence only propositions can be known. But since the range of the real and the range of the knowable coincide—or, alternatively put, since the set of all real objects and the set of all knowables is the same set—then given the doctrine of immediate apprehension, the character of reality itself is propositional. Even God is a proposition because He is thoroughly known to Himself! Hence only propositions exist and Clark’s Idealism is a thoroughgoing rationalistic Idealism. No mental entity can be accommodated that is not a proposition.
And fourth, if all reality is propositional, we come to understand Clark’s view of how one reality relates to another. Propositions, it would seem, relate only by logic. Propositions are not spatio-temporal objects. They are not facts or events. Unlike spatic-temporal objects, propositions do not occupy space or take up time. Unlike facts, they may be false. And unlike events, propositions do not occur and befall objects. Thus propositions do not interact causally: they do not affect one another by gravity or electro-magnetism, they cannot bump into one another, fall off shelves, or shatter. Clark’s propositions, rather, relate by logical implication, and they form, presumably, the one coherent system of truth. As such, Clark’s world of “men and things” is held together (sustained) by logic"(Hoover)
Thus, Clark is an idealist. But he is a peculiar kind of idealist. He is an idealist who believes that the only sorts of things which exist are the mental entities known as 'propositions.' Since propositions are inherently mental or ideal objects, it follows that Clark is a kind of idealist.
So much for those forms of the coherence theory of truth founded upon metaphysical idealism. Brand Blanshard was a coherentist whose justification for holding to a coherence theory of truth was more epistemological than meteaphysical. For Blanshard, "a coherence theory of justification leads to a coherence theory of truth"(Young 2013). Blanshard held that a belief can be tested for its truth by virtue of its coherence with other beliefs. Young notes that this standard by which Blanshard tests truth is ultimately fallible. Just because a belief is consistent with a set of beliefs does not mean that it is true. It is plausible to be able to think of a belief that is consistent with a set of truths that is nonetheless not necessitated by these truths, and does not correspond with reality. Indeed, it is possible that such a belief's coherence with a set of beliefs is illusory.
A form of the coherence theory of truth that has become popular among analytic philosophers is that argued by some of the logical positivists whose epistemological positions we have surveyed. It is precisely this form of the coherence theory of truth (which, as Young points out, is dependent upon the coherence theory of justification) that is essentially a coherentism necessitated by an epistemology which sees belief as always taking place within a context of other beliefs. Hempel and Neurath all believed that our our beliefs were constituted in a sort of web of mutually supporting and mutually dependent beliefs.
Each of these beliefs are either arbitrary and unjustifiable, or dependent upon at least one (but usually more) arbitrary and unjustifiable belief. Each one of these beliefs are potentially revisable, and therefore, the beliefs which depend upon them are themselves potentially revisable. This is a particularly radical form of fallibilism. Each proposition takes place within a set of beliefs, but we can never get beyond our beliefs. Such a coherentism "is based on the view that we cannot "get outside" our set of beliefs and compare propositions to objective facts"(Young 2013). In other words, as Van Til emphasizes throughout his works we can never interpret the 'facts' in a purely neutral manner. We are always guided by our presuppositions and biases. The way this has been phrased in analytic philosophy circles is by saying that all observation is theory-laden. The coherentist theory of justification, which we will examine in more detail later, is worth mentioning at this point, due to its tendency to, like the coherence theory of truth (apart from a non-theistic basis) lead to epistemic relativism. Quine's articulation of this epistemological position in particular emphasizes the structural dimension of epistemology. The coherentist understanding of justification is conceived of as a 'web' of beliefs, as opposed to the foundationalist picture of knowledge as constituted by a top-down vertical structure, each of whose deductive inferences can be traced ultimately to a non-inferential foundation. "This argument, like Blanshard's, depends on a coherence theory of justification. The argument infers from such a theory that we can only know that a proposition coheres with a set of beliefs. We can never know that a proposition corresponds with reality"(Young 2013). To be consistent is not to be correct.
The most obvious problem with such a version of the coherence theory of truth, as Young points out, is that it is dependent upon the coherence theory of justification, such that it is vulnerable to any critique to which the coherence theory of justification is itself vulnerable. Young points out that "We cannot infer from the fact that a proposition cannot be known to correspond to reality that it does not correspond to reality"(Young 2013). Our theories may be true even if they cannot count as knowledge due to lack of justification. Fair enough, but although a coherentist may have truth, it does not mean he can have knowledge. His true beliefs will only ever be incidentally true, for want of justification. Indeed, one of the main goals of coherence theorists is to argue that "propositions cannot correspond to objective facts, not merely that they cannot be known to correspond"(Young 2013). This is relatively easy for the metaphysical idealist, since such an idealist believes that reality consists of ideas, such that it is a nonsense statement to say that our beliefs must correspond to an external, mind-independent reality when the very existence of a mind-independent reality is regarded as specious. The essence of the debate between correspondence theorists and coherentists, thus, is that "the correspondence and coherence theories have differing views about thet nature of truth conditions"(Young 2013). For the correspondence theorist, a belief is true if it corresponds to the external world. For the coherentist, a belief is true if it is coherent within a set of beliefs. Once again, such a notion makes the most sense within the context of metaphysical idealism, since the specified set of propositions consists of those ideas in the mind of an omniscient and infallible God. Apart from such a specified set, each person can have a proposition that coheres with his or her own specified set, which may flatly contradict another person's specified set. This could arguably entail the denial of the laws of identity, non-contradiction and excluded middle, such that two mutually exclusive or contradictory propositions could be true since they cohere with a specified set of propositions. Indeed, this was Bertrand Russell's position:
According to the specification objection, coherence theorists have no way to identify the specified set of propositions without contradicting their position. This objection originates in Russell (1907). Opponents of the coherence theory can argue as follows. The proposition (1) ‘Jane Austen was hanged for murder’ coheres with some set of propositions. (2) ‘Jane Austen died in her bed’ coheres with another set of propositions. No one supposes that the first of these propositions is true, in spite of the fact that it coheres with a set of propositions. The specification objection charges that coherence theorists have no grounds for saying that (1) is false and (2) true (Young 2013).
Young notes that "Some coherence theorists maintain that the specified system is the most comprehensive system"(Young 2013). We would certainly expect this to be true of an idealist or a presuppositionalist. The specified set are those ideas in the mind of God, which is a maximally comprehensive system because of the omniscience of the mind of God. Coherentists whose specified set terminates merely upon the human mind due to its exclusion of God from their worldview make knowledge impossible; a point similar to that ably made by Van Til in essay "God and the Absolute," contained in his book "Christianity and Idealism." Unless one either knows everything, or knows someone who knows everything (in which case truth-conditions consist of correspondence to the ideas of that Person), one cannot know anything at all. Van Til argues that this is as much the case for the idealists as it is for the pragmatists, whose metaphysical pluralism, and the epistemological skepticism which necessarily followed from it, the former attempted to escape.
It is the Christian worldview which alone is able to escape the coherentist problem according to which "Coherentists can only, unless they are to compromise their position, define comprehensiveness in terms of the size of a system. Coherentists cannot, for example, talk about the most comprehensive system composed of propositions which correspond to reality"(Young 2013). The reason for this is that to speak of a proposition corresponding to reality is to be a correspondence theorist. But if the coherentist is an idealist (or so the idealist thought of themselves) or a presuppositionalist Christian, then reality is the sum total of the thoughts of an omniscient God, which is itself the specified set. This specified set does not correspond to another reality. It is reality, and the thoughts of the human mind must correspond to it in order for their thoughts to be true.
Young, defending coherentism, argues that
Although some responses to the Russell's version of the specification objection are unsuccessful, it is unable to refute the coherence theory. Coherentists do not believe that the truth of a proposition consists in coherence with any arbitrarily chosen set of propositions. Rather, they hold that truth consists in coherence with a set of beliefs, or with a set of propositions held to be true. No one actually believes the set of propositions with which (1) coheres. Coherence theorists conclude that they can hold that (1) is false without contradicting themselves(Young 2013).
Yet according to which, or whose, standard, is the specified set of propositions the preferable one? On the grounds that it corresponds to an objective reality? Of course not. As Neurath, himself an advocate of a form of the coherentist theory of truth, admitted, one set of propositions cannot be justified any more than any other. Pragmatic coherentists cannot define truth as consistency, because there is no objective or transcendent standard according to which the superiority of one set of propositions can be preferred over another. The positivists whom we have discussed seem to acknowledge that their coherentism commits them to fallibilism and epistemological relativism. And this is precisely the point. We ought not to object to such coherentists that one can never know which specified set of propositions correspond to reality, since the secular coherentist rejects such correspondence truth-conditions. Instead, we would argue that there is no transcendent criteria according to which we can determine which set of propositions is specifiable. It is the presuppositionalist, and him alone, who can be a consistent coherentist, since the nexus and standard of our specified set terminates upon the mind of an Absolute, invariant, immutable and eternal God. The coherentism of a Neurath or a Kuhn or a Quine is a coherentism that is human-all-too-human, and must commit such a coherentist to utter relativism. The correspondence theorist may object that truth is totally mind-independent. A fact is a fact regardless of who believes it is a fact. Young notes that theistic coherentism is inoculated from such a criticism since "Every truth coheres with the set of beliefs of an omniscient being"(Young 2013).
Coherence theorists can defend their position against the transcendence objection by maintaining that the objection begs the question. Those who present the objection assume, generally without argument, that it is possible that some proposition be true even though it does not cohere with any set of beliefs. This is precisely what coherence theorists deny. Coherence theorists have arguments for believing that truth cannot transcend what coheres with some set of beliefs. Their opponents need to take issue with these arguments rather than simply assert that truth can transcend what coheres with a specified system.
Indeed, coherentism seems to necessitate some form of idealism in the degree of place it gives to the subject. Of course, according to the subject a significant, if not total, conditioning role with respect to the truth is not problematic if that mind happens to be the mind of an omniscient, eternal and immutable God. But if the coherentist's worldview lacks such a perspective, it accords to the human the arbitrary truthmaker. This sounds like quite an unusual position for a non-theist to adopt. The only way to avoid this, it would seem, is for the non-theist to be a correspondence theorist:
Thagard's argument seems to be that if there is a mind-independent world, then our representations are representations of the world. (He says representations “should be” of the world, but the argument is invalid with the addition of the auxiliary verb.) The world existed before humans and our representations, including our propositional representations. (So history and, Thagard would likely say, our best science tells us.) Therefore, representations, including propositional representations, are representations of a mind-independent world. The second sentence of the passage just quoted suggests that the only way that coherentists can reject this argument is to adopt some sort of idealism. That is, they can only reject the minor premiss of the argument as reconstructed. Otherwise they are committed to saying that propositions represent the world and, Thagard seems to suggest, this is to say that propositions have the sort of truth-conditions posited by a correspondence theory. So the coherence theory is false (Young 2013).
Indeed, Colin McGinn takes the position that some form of idealism (which he rejects) necessarily follows from coherentism:
Colin McGinn has proposed the other new objection to coherentism. He argues (McGinn 2002: 195) that coherence theorists are committed to idealism. Like Thagard, he takes idealism to be obviously false, so the argument is a reductio. McGinn's argument runs as follows. Coherentists are committed to the view that, for example, ‘Snow falls from the sky’ is true iff the belief that snow falls from the sky coheres with other beliefs. Now it follows from this and the redundancy biconditional (p is true iff p) that snow falls from the sky iff the belief that snow falls from the sky coheres with other beliefs. It appears then that the coherence theorist is committed to the view that snow could not fall from the sky unless the belief that snow falls from the sky coheres with other beliefs. From this it follows that how things are depends on what is believed about them. This seems strange to McGinn since he thinks, reasonably, that snow could fall from the sky even if there were no beliefs about snow, or anything else. The linking of how things are and how they are believed to be leads McGinn to say that coherentists are committed to idealism, this being the view that how things are mind-dependent (Young 2013).
As I have argued, I believe that the only intellectually defensible form of idealistic coherentism is that of Christian theism, where truth is conditioned by being a thought in the mind of an omnipotenet, eternal, immutable God. Non-theistic forms of (necessarily idealistic) forms of the coherence theory of truth take the form of a kind of quasi-Berkeleyan idealism which secular coherentists cannot possibly assent to if they are to maintain any intellectual respectability.
Let's look briefly at the correspondence theory of truth, since as we have seen, Van Til professed allegience to it. The correspondence theory of truth is one of the main competitors with the coherence theory of truth which we have just outlined. This theory simply states that a proposition is true if its truth-value corresponds to the reality of which it speaks in the external world. For Van Til, an utterance is true if it accurately reflects the content of God's mind. G.E. Moore and Bertrand Russell were early 20th century advocates of the correspondence theory of truth (though their version of it was obviously not theistic). Like other epistemological views, this view of truth tends to be associated with specific metaphysical views: "The correspondence theory of truth is often associated with metaphysical realism. Its traditional competitors, coherentist, pragmatist, and verificationist theories of truth, are often associated with idealism, anti-realism, or relativism"(David 2013)
Aquinas was another well-known proponent of the correspondence theory of truth, having obtained it from Aristotle. He (perhaps incorrectly) credits his understanding of this epistemological view to Isaac Israeli. Truth is neither in the mind itself nor in the thing of which the mind is thinking, but rather, in the correspondence of the content of the former to the reality of the latter (David 2013). Other Aristotle-influenced thinkers who developed a version of the correspondence theory of truth include Avicenna and Averroes (David 2013). Aquinas held not only that thoughts could be true, but that individual "persons" could be true. Influenced by Jhn. 14:6, medieval theologians believed in general that a friend, for example, was "true" insofar as the person corresponded normatively to the mind's conception (either God's mind or man's mind) to what a friend ought to be (David 2013).
Aquinas' noetic understanding of the correspondence theory of truth represents those medieval theologians and philosophers who held to the 'metaphysical' version of the theory. Other medieval authors took a more semantically-oriented version of the theory, according to which a 'mental' sentence or proposition is true insofar as it corresponds to an external reality (David 2013). The metaphysical correspondence relation is correspondingly de-emphasized in favor of correspondence of semantic signification to an external reality (David 2013). The correspondence theory of truth was taken for granted by most early modern philosophers, among both rationalists and empiricists, such as Spinoza, Descartes, Locke, Hume, Kant and Leibniz (with Berkeley being a notable exception)(David 2013). David (2013) argues that the representationalist theory of mind commits one to some form of the correspondence theory of truth. While object-based versions of the correspondence theory, which state that the "truth-bearing" item (be it a judgment or proposition or whatever) required a subject-predicate structure, this model was replaced in the 20th century by more of a fact-based model, which omitted the necessity of such a structure (David 2013).
The correspondence theory of truth became a weapon in the hands of the early analytic philosophers, like Moore, the early Wittgenstein, and Russell, against idealists, who generally held to a coherence theory of truth. The logical atomisms of Wittgenstein and Russell, which held that the world consisted of atomic facts, in particular, were developed in order to provide a metaphysics adequate to a correspondence-based epistemology, over and against the British idealists.
We speak of a "truth-bearer" as vehicle by which truth-value is conveyed. The truth-bearer may be "beliefs, thoughts, ideas, judgments, statemenets, assertions, utterances, sentences and propositions"(David 2013). As we have seen, the divide between metaphysical and semantic versions of the correspondence theory of truth among medieval theologians was grounded in the fact that they each postulated distinct truth-bearers. For the metaphysical correspondentists, the truth-bearers were thoughts. For the semantic correspondentists, they were mental 'sentences.' The truthmaker, on the other hand, is that element which makes a truthbearer true (David 2013). That is, to what does a truthbearer correspond? Does it correspond to "facts, states of affairs, events, things, tropes..."(David 2013)? One's answer to this question determines which of these elements are considered the truthmakers which make a truthbearer true.
David, Marian, "The Correspondence Theory of Truth", The Stanford Encyclopedia of Philosophy (Fall 2013 Edition), Edward N. Zalta (ed.), URL = <plato.stanford.edu/archives/fall2013/entries/truth-correspondence/>.
Young, James O., "The Coherence Theory of Truth", The Stanford Encyclopedia of Philosophy (Summer 2013 Edition), Edward N. Zalta (ed.), URL = <plato.stanford.edu/archives/sum2013/entries/truth-coherence/>.
Hoover, David. "Gordon Clark's Extraordinary View of Men and Things." Web. 1984. Retrieved from: http://www.ibri.org/RRs/RR022/22gordonclark1.html