The Cross-checking of Religious Experience and the Critical Trust Approach

Kai-man Kwan

The Critical Trust Approach to Religious Experience
In recent years, there is a revival of the argument from religious experience among analytic philosophers of religion. Richard Swinburne gave it epistemological sophistication by propounding and defending the Principle of Credulity (PC) which says:
(PC)        If it seems (epistemically) to one that x is present, then probably x is present unless there are special considerations to the contrary.[1]

While William Alston does not agree with Swinburne on many (minor) points, his Doxastic Practice Approach to religious experience is structurally similar to Swinburne's. His Perceiving God is an impressive work which elaborates and defends this approach by arguing that it is practically rational to regard all socially established doxastic practices as prima facie reliable.[2] I will call this kind of approach the Critical Trust Approach (CTA). The Principle of Credulity is renamed The Principle of Critical Trust (PCT). The name highlights two major and interdependent components of this epistemology: 1) initial trust of our experiences; 2) critical examination of those experiences to see whether they are subject to defeaters. (The latter component is worth emphasizing because many tend to associate Swinburne's Principle of Credulity or Alston's Doxastic Practice Approach with uncritical blind trust.)[3] Although I argue that the PCT should be applied to all religious experiences, i.e., they are prima facie justified, I have no intention to defend the thesis that they are in the end all veridical. In this paper my defense will focus on a sub-type of religious experience, the experience of God or theistic experience (TE in short).

While Plantinga’s externalist approach is quite different from Swinburne’s broadly internalist one, his epistemology also has some parallels with the CTA. He says, “Prior to philosophical reflection, … most of us assume that many of our perceptual judgments do constitute knowledge; this assumption is one of those natural starting points for thought …; and the rational stance is to accept it unless there are sufficiently powerful arguments against it” (Plantinga 1993, 90). So Plantinga seems to agree that our sense experience (SE) is prima facie justified.

Moreover, he thinks that in SE “there is a sort of nonsensuous experience involved as well, an experience distinct from the sensuous experience but nonetheless connected with the formation of the belief in question. That belief has a certain felt attractiveness or naturalness, a sort of perceived fittingness; it feels like the right belief in those circumstances” (Plantinga 1993, 92). This can be regarded as a kind of “impulsional evidence”: “a sort of felt inclination or impulsion toward a certain belief”; “suppose we add this inclination to believe, this believed attractiveness, or inevitability, or fittingness of the proposition in question in the situation in question: suppose we think of that as evidence as well… then whenever it seems to you that something is so, you do indeed have evidence for it” (Plantinga 1993, 192). This idea in fact has affinity with Swinburne’s concept of epistemic seeming, and the last statement is similar to the PCT. Of course, Plantinga insists that impulsional evidence is not sufficient for warrant: “there must also be proper function” (Plantinga 1993, 193).

Lastly, Plantinga thinks that this kind of nonsensuous experience (impulsional evidence) is not only present in SE, but also associated with our memory beliefs, a priori beliefs, beliefs about the mental states of other persons, inductive beliefs, testimonial beliefs, moral beliefs and belief in God. In this way Plantinga is moving towards a kind of Reidian foundationalism which takes many kinds of beliefs to be properly basic (Plantinga 1993, 183-84). This is again structurally similar with Alston’s Doxastic Practice Approach and Swinburne’s CTA. It is interesting to observe that while Swinburne, Alston and Plantinga differ in their formal epistemological approaches, they in the end come to the same conclusion that a narrow kind of empiricism is untenable, and we should broaden our epistemic base quite a lot.

Alston’s argument can be regarded as a kind of Transcendental Argument for Theistic Experience (TA) which can be formulated in this way:
TA1)    Any justification from experience is possible only when the PCT is presupposed.
TA2)    Hence the PCT should be applied to all kinds of experience.
TA3)    Hence the PCT should be applied to TE, i.e., it is prima facie justified.
TA4)   Not all TEs have been defeated, i.e., shown to be delusory.
TA5)    Therefore, some TEs are ultima facie justified.

It should be noted that the Transcendental Argument for Theistic Experience (TA) is different from the Analogical Argument for Theistic Experience (hereafter abbreviated as AA) which has also been put forward by some theists:
AA1)   Sense experiences are prima facie justified.
AA2)   Theistic experiences (TEs) are sufficiently analogous with sense experiences.
AA3)   Hence TEs are also prima facie justified.

According to John Hick, "Many of us today who work in the philosophy of religion are in broad agreement with William Alston that the most viable defense of religious belief has to be a defense of the rationality of basing belief (with many qualifying provisos which Alston has carefully set forth) on religious experience."[4]  Of course, there are also many who reject this approach. In this paper, I will look at one important objection raised by Evan Fales concerning the need for cross-checking.[5]

Evan Fales’ “No Cross-checking Objection”
Fales and Alston have an interesting debate on the validity of religious experience in the recently published Contemporary Debates in Philosophy of Religion (Fales 2004; Alston 2004). Fales vigorously presses a kind of “No Cross-checking Objection” (NCO) against Alston:
NCO1)    Any kind of perceptual experience is prima facie justified only if it can be cross-checked.[6]
NCO2)    Religious experience is prima facie justified only if it can be cross-checked.
NCO3)    Religious experience cannot be (adequately) cross-checked.
NCO4) Therefore, religious experience is not prima facie justified.[7]

The conclusion NCO4 follows from the preceding premises, and it contradicts both TA3 and AA3 in the above arguments. NCO2 is a special case of the general claim NCO1. So the crucial premises here are NCO1 and NCO3. They will be critically examined later. Now let us first clarify the concept of cross-checking. Fales explains, “Let ‘cross-checking’ denote all those procedures and strategies we use to settle questions about the causes of something. …(1) using Mill’s methods to pick out causally relevant antecedent conditions; (2) exploiting the fact that events have multiple effects, to ‘triangulate’ the event in question, on the principle that qualitatively different causes will have some differences in their (potential) effects; and (3) confirming the existence of causal mechanisms allegedly connecting a cause to its effects (when it is not a proximate cause). …putting forward hypotheses and testing them by means of diagnostic experiments” (Fales 2004, 147-48).

NCO1 says that the availability of crosschecking is a necessary condition for any perceptual experience to be prima facie justified: “cross-checking…is a mandatory feature of any recruitment of perceptual experience to epistemic ends” (Fales 2004, 147).[8] But why does Fales think so? The necessity of cross-checking “derives largely from the general truth that any effect – hence a perceptual experience – can be caused in more ways than one” (Fales 2004, 147). So “what a perceiver takes to be present on the basis of her experiences might not be what is in fact causally responsible for those experiences” (Fales 2004, 152). To remove this ambiguity we need cross-checking. This “is a matter of narrowing down the candidate causes of an experience so that – ideally – just one cause, situated in the right way can explain our data. It is precisely here that cross-checking plays the crucial role by enabling us to eliminate possible causes and to form a sufficiently precise conception of our environment and the causal processes that occur in it to “zero in” on the (or a) ‘suitable’ cause” (Fales 2004, 150).

Now there is an obvious objection: “Perceptual knowledge seems much more direct than this accounts allows it to be.” However, Fales thinks that “this is an illusion, that in fact warrant accrues to perceptual beliefs only insofar as, rationally reconstructed, their acquisition, too, requires inference to the best explanation” (Fales 2004, 149). Only because “[i]n everyday contexts, cross-checking is … so automatic, continuous, and pervasive that…it is scarcely noticed” (Fales 2004, 147). The above phenomenological objection ignores “what we might call ‘subliminal information processing,’ both past and occurrent, and the vital role that cross-checking plays in this processing. What sort of perceptual seemings a given environment can produce in one is a function not only of recent sensory stimulation, but of much else: of attention and motivational factors, of past experience and concepts thereby acquired, of expectations for which an inductive rationale could be supplied if required” (Fales 2004, 150).

Another crucial premise is NCO3 which asserts that religious experience can’t be cross-checked. Fales argues that “mystical experiences are not public. Moreover, the sorts of checks typically invoked, by Christian mystics at least, are either epistemically irrelevant or question begging, absent quite strong auxiliary assumptions” (Fales 2004, 155). For example, he discusses Teresa of Avila’s four tests: (1) the fruits of an experience – both in the actions and personally of the mystic and as producing an inner peace rather than a troubled state of mind, (2) the vividness of the memory of the experience, (3) conformity to scripture, and (4) validation by the mystic’s confessor.” His major criticism is that “most such tests aim at social acceptance within the religious community. These, and all the other tests of which I know, are such that passing them is largely under the control of the mystic or of her religious community. Thus, unlike proper cross-checks, they do not risk invalidation of the tested hypothesis by an uncooperative tester-independent world” (Fales 2004, 156). So “such cross-checks as have been performed on MEs do not confirm them. Those cross-checking procedures that are internal to mystical practices are (with one exception) not of a sort that could genuinely confirm MEs, because they either have no apparent evidential bearing at all, or because they can be brought to bear only by making ancillary theological assumptions that are themselves not subject to independent tests, or because they confirm at least equally well some naturalistic hypothesis. …Nor are there cross-checking procedures external to mystical practice that support it. Indeed, until theists formulate serious, testable hypotheses concerning the manner in which God provides theophanies, there is not much that can be done along these lines” (Fales 2004, 163).

Prelimimary Clarification of Fales’ Objection
Fales emphasizes that “not all mystical experiences can be relied upon; many are the stuff of delusion. So they have somehow to be checked out…they must indeed be cross-checked to serve as good evidence” (Fales 2004, 146). The major complaint seems to be that we have no (clear or precise) criteria to find out which TEs, if they are delusive, are really so. I call these criteria of veridicality (abbreviated as CV). In particular Fales thinks that the CV have to include the ability to be cross-checked, and he objects that this criterion of veridicality is not applicable in the case of TEs. This objection can take many forms, and the allegation of ‘no cross-checking’ can mean several things:
1) no cross-checking at all!
2) no cross-checking which is non-circular!
3) no cross-checking which is like that of SE!

The second and third claims are at least implicit in some of Fales’ comments. Fales does not press the first claim because he knows this claim is apparently false. For example, Fales discusses the tests suggested by Teresa of Avila. So it is just not true that the God-experient will accept every experience of God (TE) as veridical.

The reason why lack of criteria is regarded as damaging is again not uniform. In relation to the TA, the no cross-checking objection can conceivably cut in several ways:
1) It can be meant to show that the PCT or the like should not or need not be applied to TE. It would be a denial of the premise (TA3).
2) It can be meant to show that either TE is unreliable or unjustifiable, i.e., it would amount to a denial of the premise (TA4). This can be due to different reasons:
a) Criteria of veridicality are intrinsically related to the reliability or justifiability of a type of experience.
b) Lack of criteria of veridicality shows an invidious disanalogy with SE.
Fales seems to argue for both of the above objections.

Type- veridicality, Token-veridicality and Type-reliability
In order to clarify the issues, I propose to make the distinction between type-veridicality and token-veridicality. Type-veridicality is the verisimilitude of the basic ontology of the type of experience. So theistic experience is type-veridical if there is a being whose nature is quite like that of God, as believed by the major theistic traditions. In contrast, we can consider the token-veridicality of a particular theistic experience, e.g., Paul's vision of the Resurrected Christ. We can further define 'type-reliability' of a type of experience as the probability of a token of that type to be veridical. Clearly this is a continuous variable which takes a value from 0 to 1. When we say loosely that a type of experience is type-reliable, it may mean only that the probability is larger than 0.5. The question of type-veridicality is in principle separable from the question of token-veridicality. One case of token-veridicality is sufficient to establish the type-veridicality. So the type-veridicality of a type is compatible with gross unreliability of the type. However, even in this case the type of experience is not necessarily absolutely unreliable and evidentially irrelevant. In this essay, when I speak of a type-veridical experience, it is also implied that at least a handful of the tokens are veridical.

Let us now raise the question of the epistemological relevance of the CV. Consider this argument:
A) If there are no CV to distinguish the veridical tokens from the unveridical ones, then we can't know which tokens are veridical.
B) If we can't know which tokens are veridical, then we can't know whether the type is veridical.
C) Hence if there are no tests or cross-checking, then we can't know the type-veridicality thesis.

The general idea is that for a type of experience to be evidential, tokens of it have to be evidential. However, if we allow that the tokens can be unveridical, then only the veridical tokens can be evidential. But if we can't distinguish the veridical tokens from the unveridical, then we have no access to the evidential base. Perhaps this kind of reasoning is behind the No Cross-checking Objection to TE. If the objection is interpreted in this way, one reply is that we do have CV for TE which are established in analogous ways to the case in SE. I will explore this later. Now I suggest that we do not need to decide the token-veridicality in each and every case before the type-veridicality thesis can be judged to be plausible. To make a case for the latter, we only need to show that it is unreasonable to believe that token-unveridicality is universal. Consider this argument:
D) If any token of a type is token-veridical, then a type of experience is type-veridical.
E) If it is reasonable to believe that a type of experience is not type-veridical, then it is also reasonable to believe that no token of that type is token-veridical.
F) It is not reasonable to believe that no token of that type is token-veridical, i.e., all token experiences are totally delusory.
G) Hence it is not reasonable to believe that the type of experience is not type-veridical.
I suggest this argument can work for TE. The crucial premise, of course, is (F). It seems to me and some others, e.g., Gutting, that (F) has strong intuitive appeal. Although it may be hard to produce a formal argument for (F), it is nonetheless compelling after we have surveyed all the relevant evidence. It is not necessarily dependent on demonstration of token-veridicality of a particular TE. Yet when we ponder the numerous TEs, their enormous effects sometimes, the honesty of the witnesses, the depth dimension of life and so on, it seems hard to believe that all of them are delusory. Moreover, we may also encounter the life story of a person who has dramatic experiences of God throughout his life. We also find that the person is honest, sane, wise and intelligent, and his story corroborated by many others' stories throughout history in many countries. Isn't it rash to say that all of them are entirely and chronically deluded?  Ordinary people may also find it hard to produce an explicit and water-tight argument for his belief that the earth is round rather than flat. Yet we won't deny that their intuitive judgment, which is based on many empirical clues, is rational. Can't we also claim that some ordinary believers in God, which have access to the relevant experiential evidence for God, can be rational in judging that (F) is true? 

Nevertheless, it would be nice if we can put forward a philosophical argument to back up the intuitive judgment. (F), when applied to TE, is roughly equivalent to "it is not unreasonable to believe that at least one token TE is veridical."  This is exactly the conclusion I am trying to defend via the CTA. I will suggest and defend the criteria for judging when a token TE is veridical. Of course, we can then point to a particular TE and argue for it. However, I would prefer another strategy: let us point to a collection of TEs and suggest that it is reasonable to believe that at least one of them is veridical. I would choose this subset of TE: experiences of the presence of God. Firstly, the claim of this TE is more modest and it is not liable to be in serious conflict with many TEs or non-TEs. Secondly, it is quite widely shared cross-culturally and across the epochs. Many spontaneous experiences of non-believers are also similar to this sense of presence of God. (Hay)  Thirdly, these TEs usually occur spontaneously in very diverse situations to many different kinds of people which are not in abnormal psychological or physiological conditions. This would make the naturalistic explanation of all these quite difficult. So it seems to me this sub-type of TE is least problematic and it is easier to argue that it is undefeated. My conclusion is that (B) is false: even if we cannot pinpoint one particular token as veridical, we can still argue that some token or other can be reasonably judged to be veridical and hence the experience is type-veridical. There is no intrinsic connection between having precise CV and the justifiability of a type of experience.
My strategy can have a parallel in SE. Some argue for the veridicality of SE by the Paradigm Case Argument. The idea is that when we decide the veridicality of a type of experience, we should not focus on the most problematic tokens, e.g., the optical illusions. Instead we should concentrate on the least problematic tokens, i.e., the paradigm cases. However, it seems to me this move is best construed as pointing to a subset of SE which is regarded as paradigmatic and then arguing that at least one token of this is veridical. It is not so wise to stake the argument on a particular SE. Moore has once given this example of his certain beliefs: there were windows behind the curtains in the hall where he was lecturing. It turned out to be false. What is mistaken here is not exactly a SE but I hope the idea is clear. If we point to a particular table in front of us, isn't it genuinely possible that later on a much more convincing sequence of SEs would disconfirm that?  For example, later experiences of similarly 'high quality' may suggest to one that the table was only dreamt of. However, this sort of possibility wouldn't disprove the claim that at least one of these 'high quality' SEs is veridical.

Criteria of Veridicality of Sense Experience and the Critical Trust Approach
Let us explore further the question how we can determine and justify some CV in the first place. The purpose is to show that the CTA provides a plausible way to explain the whence of our CV even in the case of SE. Moreover, this approach does not short-circuit the crucial justificatory procedures of cross-checking, as Fales accuses, but in fact makes those justificatory procedures possible in the first place and gives them an important role to play afterwards.

Let me first provide the overall view of the Critical Trust Approach:
1) Data Gleaning- Trust:
The data for the CTA are all our experiences, which are defeasible. They only have presumptive weight- let us call them presumptive data.

2) Data Sifting and Epistemic Ascent- Critical Trust:
a) Ground level sifting
The presumptive data can be defeated by reasons which show their unreliability. Typically the defeater itself is defeasible and there can be a defeater-defeater. Again the defeater-defeater is defeasible and there can be defeater-defeater-defeater and so on. So we have to bring in coherence considerations to determine the weight of each presumptive datum. Once a presumptive datum coheres with many other presumptive data, its weight would be increased and it can serve to defeat another less weighty presumptive datum. A presumptive datum which conflicts with many other presumptive datum is then defeated. In general, we can formulate this methodological rule:

The Rule of Ground Level Sifting
Always choose the consistent subset of our presumptive data which has maximal weight.

b) Explanatory Ascent and Feedback Sifting
The data of experience (of various kinds) need to be ordered, explained and made more intelligible. So the data of sense experience, when subjected to the search for order and intelligibility, yield the scientific framework. However, the framework itself can have feedback effect on the initial data. Some presumptive data of sense experience may be rejected due to theoretical reasons. Swinburne proposes the Principle of Simplicity here. His strategy is that a prima facie justified belief is successfully defeated when it is in conflict with the simplest theory compatible with a vast number of data obtained by supposing in a vast number of other cases that things are as they seem to be. In general, when the presumptive data conflict and the best explanation cannot comprehend all the data, our best explanatory theory can serve as defeater of those 'recalcitrant' data.

c) Second Order Critical Principle
When we trust the majority of our presumptive data, those data may suggest to us that some types of presumptive data are not altogether reliable. For example, those presumptive data are found to be grossly inconsistent or they are contradicted by other well-established data. In such cases, we can formulate second order critical principles. These principles are critical because they tell us under some circumstances certain presumptive data are better doubted than trusted. They are second order principles because the justification of these principles depend on our basic trust of our presumptive data which is prescribed by the first order Principle of Critical Trust.

d) Consensus and Testimony
Our data consist of personal experiences as well as testimonies. The Principle of Testimony dictates that others' testimonies are also presumptive data for one. Hence consensus does have a part to play:

Principle of Consensus:
When an epistemic seeming is consensually corroborated, it is justified to a much higher degree.[9]

3) Cognitive Adjustment:
When a prima facie justified belief is defeated, what kind of cognitive adjustment should we make to our original cognitive structure?  All other things being equal, if we accord prima facie justification to our original experience, we should reinterpret the original experience so as to preserve as much truth in the original experience as possible:

Principle of Conservation:
When an experience is defeated, it is rational to salvage as much noetic content as possible from that epistemic seeming, i.e., to retain the highest undefeated level of epistemic seeming embedded in that experience.

Now let us go back to the problem of the whence of CV in SE. Consider these two statements:
1) We possess some criteria of veridicality.
2) We can identify tokens of veridical experiences.
Which is logically prior, (1) or (2)? Neither option seems palatable. If we don't know how to identify tokens of veridical experiences, it is hard to see how we can arrive at some CV. But if we don't have some CV and our experiences are fallible, how can we identify tokens of veridical experience?
Suppose (1) is logically prior. Obviously we are faced with the problem how we arrive at those CV. Nobody would suggest that they are revealed by God or some angels. Perhaps the relevant criteria are conceptually derived from the ontology of physical objects in space-time. Gale seems to adopt a similar line. He argues that all the relevant tests can be derived from the nature of physical objects and space-time. Now let us take Gale's understanding of the nature of physical objects as given and explore his position. Can the tests solve the sceptical problem?  According to him, from the nature of the physical objects, we can derive these results: if a SE is veridical, then we can predict future SEs of the subject and others and the subject's sensory faculty is in good working order and he is in the proper spatio-temporal position to perceive the apparent object of the SE and so on. (He gives 11 tests altogether.)  Suppose these criteria are formulated:
If the prediction is borne out and the man is in the proper position and so on, then the SE is probably veridical.
If the prediction is not borne out or the man is not in the proper position or ..., then the SE is probably unveridical.

Now the same problem afflicts him: we cannot ascertain whether the CV are satisfied apart from some basic trust in SE. Moreover, CVn seems to be more secure since they follow from the above theory about physical objects. It is otherwise for CVp. If we are just given the theory about the physical objects and not their existence, then the satisfaction can be explained by the sceptics as well. The theory need not be about some actually existing things: it can be in the mind of the evil scientist instead. Perhaps the evil scientist is also a good philosopher: he first lays down some ontological descriptions of the nature of 'physical objects' and then derives the principles which govern the 'veridicality' or 'unveridicality' of SEs. These principles are then used as the most basic axioms of his program which governs the inputs to a brain-in-a-vat. (Of course he also needs to draft some contingent causal laws which conform to the axioms.)  In this way all the experiences of the brain-in-a-vat would indeed conform to Gale's theory of SE. Perhaps the brain-in-a-vat also reasons as Gale does and concludes that all his experiences must be real?! So Gale's tests are not an adequate reply to scepticism. However, his discussion certainly shows further the coherence of SE. It is because the tests need not be passed by our experiences and the fact that they are frequently passed is impressive. The result is that if the basic trust in our SE is justified, then unveridical SEs are indeed much easier to weed out. This would increase the internal coherence of SE.
Now I have to raise the question: how Gale's understanding of physical objects is derived from the first place?  Perhaps we can rely on the grasp of some a priori necessary truths.[10]  But they do not seem to be sufficient to sustain such a detailed theory like Gale's. For example, Gale assumes that physical objects have a sort of stability and universal accessibility to persons. I don't think it is an a priori truth. To establish this our experiences themselves are also indispensable. Without prior trust in those experiences, can we trust the theory derived from them? All these questions push us to take seriously the case that (2) is prior to (1). We have a priori principles which justify our basic prima facie trust in our SEs. The veridical tokens are then established by the ground level sifting. Only after that we can investigate the perceptual conditions of veridical SE and the nature of the physical objects. Of course, this knowledge would help us lay down our criteria of veridicality. The process is ongoing and further knowledge may help us to modify, revise or add to our previous CV.  
If it is the correct picture, then we shouldn't expect the same CV would apply to different sorts of experience. Take interpersonal experience as an example. How is the consensus test to be applied here?  Chesterton has an example roughly like this. Suppose we are told that a young lady calls his fiancee by a very intimate nickname. Are we going to test it by summoning fifteen psychologists to observe their interaction and conversation?  Similarly, when A tells us that B told him a very traumatic experience, we would not insist that B has to tell the same experience before all of us!  It is because by the very nature of the case, these experiences, if veridical, are not likely to be publicly corroborated. So it seems to me, the following principle should be kept in mind when we decide the CV for a type of experience:
The CV for a type of experience should be appropriate to the nature of the alleged object of experience and the subject of experience.

This principle is all along operating even in SE. We tend to forget that there are many kinds of physical objects and perceivers as well. The way to test the existence of wind would be very different from that of a table, not to mention atoms, EM fields, etc. We won't apply the test of touch to a far away flying object. We won't insist that a table has to be seen by a blind man. All these illustrate the fact that our actual tests and cross-checking of a particular SE are actually context-dependent, i.e., depending on the whole perceptual context which is constituted by the subject, the object and the environment. Any change of this context would affect our decision as to which tests are relevant. It is a false picture to suggest that we have fixed, uniform tests even in SE.
Let us look at some concrete example. We seem to see a bending stick when part of a straight stick is immersed in water. We would count that as an illusion while taking the perception of the straight stick as veridical. This distinction is taught to us since our early days and most of us would take it for granted. But can we give an account of the reasons for this move?  Let us not first take into consideration the science of optics. If the optical account of the illusion is necessary for the above distinction, then we are denying the right of most of our ancestors to make this distinction. This seems most implausible. If we just consider the more common sense response, then probably the reason why the apparent perception of a bent stick is illusory is as follows: "If we take the stick out of the water, the stick again looks straight. Furthermore, if we grope for the stick partly immersed in water, it still feels straight. Therefore it must remain straight although it seems to be bent."  However, this reasoning can be doubted. For the first reason to be conclusive, it has to make two more assumptions: firstly, the visual perceptions are veridical; secondly, the shape of the stick has remained constant throughout the process. If we are prepared to grant that the stick is bent when it is partly immersed in water and it is straight when all of it is out of the water, then we can insist that both perceptions of a straight stick and a bent one are veridical. As for the tactual experience of straightness, why can't we insist that vision is more reliable than tactual experience and take the tactual experience as illusory instead of the visual one?  To settle the question in favour of the common way of interpretation we seem to need two rational principles:
Other things being equal, we should choose an interpretation of experience which fits with the simpler ontology.

Other things being equal, we should choose an interpretation of experience which would render more of our perceptual experiences veridical.

The second principle in itself is not sufficient: both interpretations would need to render some experience illusory and it does not decidedly favor the common sense interpretation. However, the common sense interpretation posits a sort of stick which would not suddenly change shape when immersed in water and this ontology is simpler. Someone may object that a stick is just not the type of object that would easily change shape. This piece of knowledge, it might be argued, is the foundation of our common sense interpretation of experience rather than my alleged rational principles. This reply won't do. It may seem obvious to us that the above statement about the stick is true but it is only so because it is repeatedly confirmed in our experiences. But given that our experiences can be illusory, can we decide what is confirmed by our conflicting experiences unless we have a way to distinguish which experiences should be counted as veridical and which illusory? The answer seems to be no. Similar questions can be raised about our knowledge of the causal powers of various things, which Fales has presupposed in his account of cross-checking. But apart from a basic trust in SE, how can we know there really are things like causes and effects, and how do we determine what kinds of causal relationship exist? All these only make sense when a CTA has been assumed.

If so, then the above principles seem to be basic principles of experiential interpretation in accordance with which we posit the veridical-illusory distinction. The first one is effectively a form of the Principle of Simplicity. The second is a variant of my Rule of Ground Level Sifting which is a corollary of the PCT. In other words, adoption of this principle already commits us to a basic prima facie trust in our experiences. If so, then my CTA can nicely account for the way we make the veridical-illusory distinction.

Similar arguments are possible for other CV. For example the consensus test is effectively the employment of the Principle of Consensus which is a corollary of the CTA. As for the test by scientific equipment, it seems to be a case of my feedback sifting. I agree that consideration of ontology comes in when we make the veridical-illusory distinction but this distinction is still prior to the knowledge of the nature of the physical world. To gain such knowledge we need to justify it by veridical experiences and hence before we can know which claims can be regarded as knowledge we need to decide which experiences are veridical. My idea is that our knowledge of the nature of the physical world is justificatorily dependent on the application of PCT to SE. Of course when it has been built up, it can be used to do feedback sifting and to formulate more precise CV. In SE, the ontology of the physical objects is believed to be correctly described by our scientific theories and that is why science can play a crucial role in confirming (or disconfirming) our common sense way of making the veridical-illusory distinction. I have earlier raised the question why, in the case of the apparently bending stick, the visual experience is taken to be illusory rather than the tactual experience of it. One powerful reason for this is provided by the theory of geometrical optics because it gives a more detailed explanation of the visual illusion by positing the process of refraction of light rays by water. On the other hand, if we take the interpretation that the stick is bent when partly immersed in water, we do not have explanations why the bending occurs and how the alleged tactual illusion of straightness occurs. (However I take this to be a contingent matter. Perhaps such explanations are not available because they have never been sought: we have already decided that the bending is not probable. It does not mean however that it is not possible that the immersion in water would cause the bending of the stick. It just isn't the case and this is confirmed by the scientific explanations.)  So another principle seems to be involved:
If two interpretations of experience both render some experiences illusory, the interpretation which gives better explanations of the alleged illusions is to be preferred.
This seems to be another example of feedback sifting by inference to the best explanation.
My conclusion is that a plausible account of the 'whence' of our criteria of SE actually fits quite well with my CTA[11]. This process of deriving the CV can be summarized:
1) Basic prima facie trust in our experiences.
2) By explanatory ascent and data sifting, we decide which types of token are more reliable and which unreliable. At this level, some preliminary CV would emerge. The CVp are basically derived by observing which tokens exhibit higher degree of coherence with the majority of other token experiences of oneself and others. The CVn are derived by observing which type of tokens conflict with the more established ones. (CVn are Second Order Critical Principles.) Investigation of perceptual conditions would help both.
3) It is possible that by further explanatory ascent, we can have a more detailed theory about the object of experience. This theory is then used to confirm, modify or revise our preliminary CV in such a way to gain overall coherence. More precise CV may then result.
So far I have argued that the lack of precise ascertainable criteria does not tend to make a type of experience unjustifiable or unreliable. Nor can it render the PCT inapplicable. So why the critics think it is so damaging?  I suggest in the end such objections may only betray the bias that all experiences should be checkable by criteria similar to those used in sensory perception. So it is the disanalogy with SE that is seen to be damaging.[12] But why should we assume all basic sources of justification have to resemble SE? This seems to be epistemic imperialism, as Alston says.

Tests for TE
In order to give a fuller reply to the No Crosschecking Objection, let us discuss the CV for TE and their justifiability. First, consider Jantzen's suggestion: "It is characteristic of religious experiences that they have qualities of intensity and great significance- so much so that typically it is felt that the experience challenges and questions the mystic to his very core, that he would be betraying his own integrity and stultifying the possibilities of his own growth if he did not take it seriously. The reciprocal questioning and deepening of understanding which then occurs contributes to the process in which self-integration and wholeness, including deeper sensitivity to the needs and suffering of others, can develop in a quality of life lived in conscious relationship to a compassionate God. Seen in this way, it makes sense of the relationship between specific experiences and the experienced quality of life, and indeed makes that life a continual testing of those experiences- and they of it" (Jantzen, 289; italics mine)  So can a mystical experience legitimately tip the balance in favour of belief in a personal God?  "Well, no: not if it is a one-off odd ecstasy without bearing on the whole of life lived. But what it can legitimately do is be part of a process of deepening understanding of oneself and others, part of which is bound sooner or later to bring about the recognition that self-transformation is in one sense necessary and in another impossible: more resources are needed than our own. ... as RE deepens into a quality of life lived in integrity, the reciprocity of encounter and response can legitimately tip the balance: it is rational for the mystic to believe in a personal God" (Jantzen, 290). Because "this reciprocity ... is part of the basic pattern of rationality, in which questioning occurs from within a perspective, but in which the answers obtained by that questioning can in turn modify that perspective, sometimes radically, leading to deepening understanding and thus to a new round of questioning" (Jantzen, 289). However Jantzen thinks it need not be irrational for one who does not himself experience a personal God to hold to a atheistic view.

Though I disagree with Jantzen's conservative estimate of the evidential force of REs, she still draws us to an important point: a TE does not just occur, at least for some, out of the blue and then disappears without a trace. It shapes a life and it has a dimension of depth that conveys a sense of reality that, at least for those who experience it, is hard to deny. Of course, I am not proposing here that this proves the veridicality of REs. It is doubtful we can ever prove the veridicality of a single experience. I am only saying we have no reason to expect the criteria of TEs should conform to the pattern of the criteria of sensory experiences[13]. If we drop this unreasonable expectation and look at the religious case, is it not clear that the tests we can reasonably expect are somewhat like the reciprocity tests described by Jantzen?  Another author, Henderson, also claims to find similar ideas in Austin Farrer: "Farrer insists that verifying evidence cannot consist in certain predilineated events which we observe. For God is unique; he makes an unconditional claim upon our devotion. To make him prove his existence through the production of happy effects would be to subvert the affirmation; it would be a subordination of God's will to ours rather than of ours to God's. ... The affirmation of God, if genuine, is a practical affirmation which runs into the activity of integrating one's own will with God's. ... through the affirmation of God we become participants in a life which surpasses also the life in community with ordinary persons. ... We verify the affirmation of God's existence, therefore, by entering into life-in-God and finding that the life can indeed be lived and lived in all circumstances and that it blesses" (Henderson, 178-79). This blessing is the "blessing of a union of will with the primal will" which is also "the fundamental blessing of finding oneself where one belongs".
Let me spell out more clearly my suggestion:
A TE of a person S is more likely[14] to be veridical if:
a) S has more TEs later in life; the probative force is stronger if these confirming TEs are more frequent and more various.
b) the original experience and the subsequent ones exhibit a high degree of coherence with the original experience. Reciprocity is a kind of consilience: the original experience and the subsequent ones lead to a continuous process of questioning and deeper understanding and further questioning and so on. The original object of TE seems to have inexhaustible richness that eludes one's expectations.
c) a substantial amount of people also have similar experiences. (The more the better.)  It is even better that the experience is shared at the same time, e.g. a corporate TE.
d) the experience is coherent, congruent or consilient with other experiences, e.g. moral or existential experiences.
e) the experience leads him on the road to self-integration, e.g. he understands himself better, leads a more fulfilling life.
f) the experience helps him to lead a morally better life, e.g. higher sensitivity to others, more loving, better moral insights, humility.
g) the experience produces a strong sense of reality which is not clearly induced by abnormal conditions or psychological processes.
h) the experience is accompanied by 'happy effects', coincidences, or miracles which are hard to explain naturalistically.

Normally, it would be objected that these tests draw on the theistic traditions' understanding of God. But I hope I have already shown that this procedure is not illegitimate. Actually in establishing the CV for any type of experience we have to follow this pattern. So let me instead explain further why these criteria hold. They seem to follow more or less straightforwardly from the categoreal nature of the object of experience, i.e., God in this case. If the experience is veridical and God exists, it seems likely that God will reveal to S further, if S is open to that. Since God can manifest in many ways, it seems more true of God's nature if S's experience is confirmed by different modalities of TE. So (a) is plausible. (b) follows from the general probative force of coherence between initially probative experiences. If God is independent and transcendent and the original experience is not self-generated, then further experiences should reveal unexpected, surprising characteristics of God and the object should appear to be unfathomable by experiences. (c) follows from the Principle of Consensus. If God is the source of all veridical experiences, a veridical experience should also be coherent with other veridical experiences. I am prepared to argue that moral experience and existential experiences should not be dismissed and they can plausibly be argued to come from God as well. If so, (d) ensues. If God's approach to man is meant to give his life meaning and wholeness and if God Himself is man's telos, a TE which achieves this is more probably veridical, hence (e). If God is also the source of community and values, then contact with him is likely to produce moral transformation, hence (f). If God is the Ultimate Reality and he can more directly act on the soul, then it is expected that genuine experience of God should have a strong sense of reality. (g) is not surprising at all. If God is the Creator, he can also perform providential acts in order to confirm his purpose, hence (h).

Now one crucial point is that the above are positive CV. (Note there is only a 'if'- not 'only if'.)  We cannot argue that if either one of the above is lacking, then the original experience is likely to be unveridical. This is not an ad hoc move. In general I deny that CVp and CVn have to be symmetrical. More positively, the asymmetry in this case is due to the fact of freedom of God and man. God may not choose to use providential acts to confirm his purpose, hence (h) can't be used as a CVn. Similarly, a man can resist further contacts with God and he may even deliberately run away from God after the first encounter. Hence (a) to (f) can't be used as CVn. However, as believers himself realize the fallibility of TEs, the lack of (a) to (h) does lessen his confidence in that particular TE. The following principle seems true:
If a large number of conditions from (a) to (h) are not satisfied, then although the TE is not thereby regarded as unveridical, it will be treated with some reserve.

A TE of S is likely to be unveridical if:
a) it conflicts with the well-established TEs (by the above criteria).
b) it conflicts with other well-established experiences, especially moral experience.
c) it leads to a disintegrated life, e.g. insanity.
d) it conflicts with well-established knowledge.

My conclusion is that we can justify and specify some CV for TE. (cf. Alston's test of sanctification)  The circularity is not damaging if the CTA is true and anyway CV for SE is similarly circular. So Fales’ objection that the CV of TE are epistemically irrelevant does not hold water.[15] He is often just reasserting his standard (NCO1) and insists on applying it to TE, without giving a proper response to Alston’s reply. I have argued in this paper that NCO1 is false, and the CTA gives a better picture of our epistemic situation. So Fales’ No Cross-checking Objection fails, and Alston’s TA emerges unscathed.

However, it should be conceded that the CV for TE are much vaguer than those in SE. The CV for SE, in some situations, can be quite precise and their applicability often produces a bootstrap which further increase its internal coherence. Cross-checking does have some epistemic significance. This is also a significant disanalogy between SE and TE. So after all there is something in Fales’ objection but he has drawn the wrong conclusion. The correct conclusion to draw is not that the TA has been defeated but that SE is more reliable than TE. In no way it follows that TE as a whole is type-unreliable or unjustified.

Alston, William. 1977. "Can Psychology Do Without Private Data?"  In John M. Nicholas, ed.,  Images, Perception and Knowledge (Dordrecht: D. Reidl Publishing Co).
Alston, William. 1991. Perceiving God: The Epistemology of Religious Experience. Ithaca and London: Cornell University Press.
Alston, William. 2004. “Religious Experience Justifies Religious Belief” and “Reply to Fales.” In Contemporary Debates in Philosophy of Religion, ed. by Michael L. Peterson and Raymond J. VanArragon (Oxford, Blackwell), pp. 135-145, 158-161.
Armstrong, D.M. and Malcolm, Norman. 1984. Consciousness and Causality. Oxford: Basil    Blackwell.
Audi, Robert. 1988. Belief, Justification and Knowledge. Belmont, California: Wadsworth       Publishing Company.
Ayer, A.J. 1977. "The Causal Theory of Perception." PAS Supplementary Vol. 1977.
Fales, Evan. 1990. Causation and Universals. London: Routledge.
Fales, Evan. 2004. “Do Mystics See God?” and “Reply to Alston.” In Contemporary Debates in Philosophy of Religion, ed. by Michael L. Peterson and Raymond J. VanArragon (Oxford, Blackwell), pp. 145-158, 161-163.
Gale, Richard. 1991. On the Nature and Existence of God. Cambridge: Cambridge University Press.
Gellman, Jerome. 2001. Mystical Experience of God: A Philosophical Inquiry. Aldershot: Ashgate.
Gutting, Gary. 1982. Religious Belief and Religious Skepticism. University of Notre Dame Press.
Hay, David. 1990. Religious Experience Today. London: Mowbray.
Henderson, Edward Hugh. 1985. "Valuing in Knowing God: an Interpretation of Austin Farrer's Religious Epistemology." Modern Theology 1:3, pp.165-82.
Jantzen, Grace. 1987. "Epistemology, Religious Experience, and Religious Belief." Modern Theology 3:277-291.
Kwan, Kai-man. 2003. “Is the Critical Trust Approach to Religious Experience Incompatible with Religious Particularism? A Reply to Michael Martin and John Hick,” Faith and Philosophy, vol. 20 no.2 (April 2003), pp. 152-169.
Losin, Peter. 1987. "Experience of God and the Principle of Credulity: a Reply to Rowe." Faith and Philosophy 4:59-70.
Plantinga, Alvin. 1993. Warrant and Proper Function. Oxford: Oxford University Press.
Rowe, William. 1982. "Religious Experience and the Principle of Credulity." International Journal for Philosophy of Religion 13:85-92.
Slote, Michael. 1970. Reason and Scepticism. London: George Allen and Unwin Ltd.
Wainwright, William. 1973. "Natural Explanations and Religious Experience". Ratio 15:98-101.
Wainwright, William. 1981. Mysticism. Brighton: The Harvester Press.

[1] Richard Swinburne, The Existence of God (Oxford: Clarendon Press, 1979), ch. 13.
[2] William Alston, Perceiving God: The Epistemology of Religious Experience (Ithaca and London: Cornell University Press, 1991).
[3] For example, Matthew Bagger has repeatedly accused Alston of adopting a protective strategy which shields religious experiences from critical scrutiny. See his Religious Experience, Justification, and History (Cambridge: Cambridge University Press, 1999), passim.
[4] John Hick, "The Epistemological Challenge of Religious Pluralism," Faith and Philosophy 14 (1997), p. 277.
[5] In fact many of the basic points have already been stated by Alston (2004), and I think he has successfully defended himself against Fales. However, their exchange raises a lot of crucial questions which need to be explored more thoroughly.
[6] Fales does not exactly talk in the language of justification. He uses the language of evidence most of the time. However, the two kinds of language are more or less inter-convertible. A kind of experience is prima facie justified if and only if it can be used as prima facie evidence.
[7] Fales does not explicitly formulate his objection in this way but the argument is clearly contained in this passage: “cross-checking…is a mandatory feature of any recruitment of perceptual experience to epistemic ends; and that, therefore, it is a requirement that must be met in theistic appeals to mystical experience as evidence for theism. …this requirement has not, and probably cannot, be met. So … mystical experience provides hardly any useful support for theism” (Fales 2004, 147).
[8] Or “the centrality of cross-checking…is demanded for knowledge of any causal process, in which causes are known via their effects. …in connection with any claim to have perceptual access to an extra-mental reality” (Fales 2004, 149).
[9] Note that this principle does not entail that when an experience is not, or even cannot be, consensually corroborated, it should then be doubted.
[10] Gale indeed appeals to some necessary truths but it is not clear how he understands the nature of such necessary truths.
[11] A similar picture emerges from the discussions of Alston 1991, pp.217ff.
[12] Fales does not explicitly assert this statement but many of his arguments only make good sense under this assumption.
[13] cf. Alston: "it is an unthinking parochialism or chauvinism, or epistemic imperialism ... to suppose the CMP (christian mystical practice) is properly assessed in terms of the checks and tests appropriate to SP (sensory practice). Judging CMP outputs on the basis of SP tests is no more appropriate than evaluating introspective, memory, or mathematical beliefs by the same tests. The objection to CMP I have been considering is guilty of the same kind of chauvinism as Plato's and Descartes's low assessment of SP as lacking the precision, stability, and certainty of mathematics and Hume's low assessment of inductive reasoning as lacking the conclusiveness of deductive reasoning. ... I have been stressing the irreducible plurality of doxastic practices in the tradition of Reid and Wittgenstein" (Alston 1991, 220)  However, I also emphasize that a general scheme like the CTA seems applicable.
[14] Remember the CVp are not meant to prove. They are formulated on the assumption of the PCT. It is possible that all the criteria are satisfied and the theistic experience still unveridical. The same goes for the CV in sense experience as well.
[15] Many of Fales’ specific criticisms are dubious. For example, is it really true that the attainment of inner peace or the approval of spiritual advisors can be easily controlled by oneself? Lack of space does not permit me to give detailed replies.