The Causal Strategy

In formulating a theory of knowledge one provides a general framework with which one can delimit a subset of a cognizer 's states--a means whereby to differentiate mental states in general from those mental states having high epistemic warrant. Using the idea that a definition of knowledge provides the basis from which to differentiate a system's epistemically praiseworthy mental states from other states, one can delineate the causal strategy for defining knowledge as follows: The causal strategy for defining knowledge requires that causal concepts play an explicit and ineliminable role in differentiating knowledge states from other states. In other words, a theory of knowledge counts as an instance of the causal strategy only if one cannot explicate knowledge within the theory without making reference to causal concepts.

Causal concepts must play an explicit and ineliminable role in any instance (theory) of the causal strategy, because in framing a theory of knowledge consistent with the causal strategy, one must show how causal notions serve (perhaps in conjunction with other concepts) to delimit the set of knowledge states. Causal concepts must constitute part of the essential core of the theory, just as reference to chocolate chips is an essential part of a chocolate chip cookie recipe. One might replace the words 'chocolate chip' in the recipe, but one cannot delete the reference.

Suppose, for example, that I define the set of knowledge states as all and only true beliefs produced by reliable causal processes. Such a definition is prima facie an instance of the causal strategy. But, what work does causality do in my definition? Suppose I answer this last question by extolling the virtues of reliable processes, explaining how reliability does all of the epistemic work necessary to produce knowledge. I then add, "Oh yes, and all processes are causal, so reliable processes must be causal as well." Were I to answer you thus, I would not be a causal strategist--at least, not a very good causal strategist. Why? First, I could just as easily delimit the set of knowledge states without causality: Insisting on causal processes in a causal world is redundant and unhelpful. Reliability does the epistemic work. Second, on such a loose construal of the causal strategy, nearly everyone turns out to be a causal strategist. Of course, the first reason is better than the second: It would be surprising to find out that Kant was a causal strategist, but more importantly, it would be unilluminating.

I use the term "causal theory" to denote a theory that is an instance of the causal strategy for defining knowledge. I use the term "traditional causal theory" to refer to those instances of the causal strategy that have actually been forwarded and defended as causal theories in the western philosophical tradition.

The causal strategy is a shared, influential strategy for understanding knowledge--a research program in epistemology. Indeed, all traditional causal theories, by requiring some or other causal connection between belief and the object of belief, introduce causal concepts and, therefore, fall under my definition of causal theories of knowledge. The assertion that r's having property P must have some causal connection to the belief that object r is P lies at the heart of traditional causal theories:

Of course, not every causal chain that ends in a belief will end in knowledge. Suppose that Joe, whom I know to be a chronic liar, sees my car lights on and informs me of the fact. Based solely upon his report, I come to believe that my lights are on. There is a causal chain from my lights being on to my belief that the lights are on. Yet, my belief does not seem to count as knowledge since I know that Joe tends to lie.

For a causal theory to correctly diagnose cases like my light belief, the theoretician must tinker with the basic causal story. This tinkering is the sole industry of the traditional causal theorist. Traditional causal theorists add various clauses to their definitions in order to exclude intuitively unsatisfactory cases like my belief based upon Joe's testimony, and to include intuitively satisfactory cases. Such additional clauses require that causal connections linking object and belief have additional properties. These clauses (and the properties that they require) distinguish one causal theory of knowledge from another:

Additional clauses usually introduce noncausal properties. For instance, Goldman (1967) requires a warranted inferential chain in cases of inferential knowledge, i.e., a chain based upon true premises that confirm the resultant belief either deductively or inductively. The addition of non-causal clauses does not disallow these augmented theories as causal theories of knowledge. However, the causal theorist must make sure that the addition of non-causal clauses do not render the causal clause empty or redundant as in the earlier reliable causal process theory.

Just as philosophers traditionally introduce supplementary (non- causal) clauses to handle problem cases, many also deal with problem cases by limiting the scope of their theories. For example, Alvin Goldman limits his (1967) causal theory to knowledge of empirical facts:

Justified True Belief and the Gettier Counterexamples

One appeal of the causal strategy lies in the fact that humans are causal mechanisms. The causal strategy has an additional appeal to the philosopher based upon its claimed effectiveness in dealing with a classic (though rather recent) problem in epistemology

Goldman's 1967 Causal Analysis

S knows that p if and only if the fact that p is causally connected in an appropriate way with S's believing p. "Appropriate," knowledge producing processes include the following:

(1) perception

(2) memory

(3) a causal chain, exemplifying either pattern 1 or 2,

which is correctly reconstructed by inferences, each of

which is warranted (background propositions help warrant

an inference only if they are true)

(4) combinations of (1), (2), and (3) (1967, pp.369-70)

Goldman goes on to assert that he leaves the list open to additions. He requires only that the processes added to the list be causal in the general way that he has specified.

Clause three contains a good deal of implicit information: To understand clause three, one must know that pattern 1 causal chains satisfy the following condition:

The fact (that P) causes the evidence from which the belief (that P) is generated by deduction or induction.

A pattern 2 causal chain satisfies the following condition:

The fact (that P) and the evidence from which the belief (that P) is generated (by deduction or induction) have a common cause.

An inference is warranted iff "...the propositions on which he bases his belief of p must genuinely confirm p very highly, whether deductively or inductively." (Goldman 1967, p.363) One must also know what it means to reconstruct a causal chain by inferences. However, Goldman remains rather vague concerning what it means to reconstruct a causal chain by in ferences, saying only that one "...must reconstruct all of the important links." (1967, p.363)

Treating Goldman's 1967 paper as an attempt to define knowledge is slightly inappropriate. Goldman describes his project as "...another analysis (or sketch of an analysis) of 'S knows that p,'...." (1967, p.357) He also refers to his analysis as a theory of knowledge. These descriptions are not equivalent to a definition in Goldman's mind. Goldman sees himself as attempting to explicate the meaning of the sentence form "S knows that p," in ordinary or common usage.

Goldman has often said that such ordinary concepts as knowledge and justification are vague and imprecise. (1976 and 1986) Hence, Goldman remains unruffled if his analysis leads to an open or incomplete definition of a term. "A Causal Theory of Knowledge" is no exception to this view. Goldman explicates knowledge in terms of three types of mental processes--perception, memory, and inference. However, Goldman informs us "...that I have not closed the list of 'appropriate' causal processes." (1967, pp.370-1) Goldman also uses the concept of "warrant" in his analysis. He then defines warrant in terms of a clearly undefined notion of very high inductive confirmation. (1967, pp.362-3)

Problems With Goldman's Analysis: Necessary Conditions

At first blush, Goldman's proposal might seem attractive. His theory is a traditional causal theory, insisting that a causal connection between the (empirical) "fact" and the belief is necessary for knowledge. Yet, one can easily discover cases where beliefs without Goldman's causal pedigree count as knowledge:1

One can get a system to detect the edges of objects by filtering light intensity arrays using a point-spread function and by comparing color measurements. Though edges often co-occur with color changes, edges do not cause changes in color. In descending a staircase one knows the location of the next step without looking. One is able to place one's foot so as to descend the staircase without tripping. But, the next stair does not cause a belief about its whereabouts. One can locate one's car in the parking lot by its accidental visual properties. The relevant property ("fact")--one's ownership of the car--does not cause one's belief that one's car is in the fourth stall.

In each of the above cases one comes to have a belief that seems to count as knowledge, yet the belief is not causally connected to the relevant object having the relevant property. Rather, the epistemic warrant of the belief seems to result from the fact that the cues upon which one base one's inferences reliably covary with the state of affairs described by the belief. I call such cases "reliable correlation cases."

In the case of one's belief that one's car is in the fourth stall, ownership does not cause the belief. Rather, some set { a,b,c } of accidental visual cues cause one's belief. In normal circumstances these cues reliably indicate the presence of the car that one owns. However, replace one's car with a car that also has visual properties { a,b,c }, replace the car with a holographic image of the car, and one still forms the same belief. Replicate the individual, and each of the duplicates form the belief that their car is in the fourth stall.

In the case of one's belief about the stair, one knows the stair's location because one operates under the assumption that stairs are propor tionally identical. The next stair is as far away from the current stair as the current stair is from the one previous. In normal circumstances the distance between the current and previous stairs reliably indicates the distance to the next stair. If one's working assumption concerning stair proportionality proved incorrect--if some builder perversely made each stair a different size and put them at a varying distances from one another-- one would fall flat on one's face epistemically and literally.

In the case of edges, color-sensitive filtering causes, in part, edge beliefs. The object's edges do not cause color changes. Nevertheless, edge beliefs count as knowledge because the results of such color-sensitive filtering can be used to reliably detect edges. That is, dramatic changes in filtered point values co-occurring with changes in color usually indicate an edge.

The edge and stair cases demonstrate that Goldman's definition fails to capture the necessary conditions for knowledge. Cognizer 's regularly generate beliefs through processes that do not succumb to an analysis of fact connected to belief via a direct causal chain.

Problems With Goldman's Analysis: Sufficient Conditions

Goldman's causal theory fails to capture the necessary conditions for empirical knowledge. Moreover, it also fails to capture the sufficient conditions for knowledge: According to Goldman, if a fact causes a belief via perception, memory, or inference, then that belief counts as knowledge. With this in mind, consider the following case:

John performs a color recognition task in which he must name the normal color of objects in a room. The room in which he performs this task is, unbeknownst to him, flooded with red light. He correctly identifies the first object, a salt shaker, as an object that is red under normal circumstances.

John's belief is caused by the fact that the object is red (which causes its red appearance). It is caused by the perceptual process. So, on Goldman's analysis John's belief counts as knowledge. Yet, under the condition of red light, John is not particularly good at discriminating colors. As it happens, the object causing John's belief is red, but he would form the same (now incorrect) red beliefs about white objects, pink objects, beige objects, etc.. His general inability to use perception to form correct color beliefs, and hence perform his designated task, surely undermines the epistemic warrant of John's red shaker belief. Goldman's conditions, therefore, surely do not constitute the set of sufficient conditions for knowledge.

Again, the color example is not atypical of normal cases of cognition: My office phone rings while I am down the hall. The ringing causes me to believe that my phone is ringing. Again, the fact (my phone ringing) causes the belief (that the phone is ringing) via perception. My belief, as a result, counts as knowledge for Goldman. Nevertheless, given that the phone in any office down the hall could have caused my belief, and that it is pretty much equally probable that any of the phones would ring, Goldman's conditions seem insufficient for my belief's counting as knowledge.

I am walking through some fields. I see a plant that looks like marijuana. I come to believe that the plant is marijuana. As it happens, the plant is marijuana. The plant could, however, have easily been any one of a dozen weeds common to the area. As I have not had much contact with marijuana plants, I would never have known the difference. Again, I met Goldman's conditions. Again, Goldman's conditions seem insufficient for knowledge.

In music class, the instructor randomly strikes a key, and I am asked to identify the note. I correctly identify the note as a C. However, I lack the ability to discriminate between a C and a C flat, a C sharp, or even a B flat. Again, my belief forming process satisfies Goldman's conditions, but it surely fails to count as knowledge. Again, Goldman's conditions prove insufficient for knowledge.2

Ad Hoc Additions to Goldman's Theory

The background theory for my critique is that of Imre Lakatos as presented in The Methodology of Scientific Research Programmes (1978).

Lakatos is interested in evaluating research programs as progressive or degenerative. Lakatos thinks of a research program as a series of theories sharing the same hard core but differing in their protective belt. That is, each successive theory shares the central presuppositions of its predecessor(s). Successive theories differ from their predecessor(s) in terms of the number and/or content of auxiliary hypotheses upon which the respective theories depend.

On Lakatos ' account successive theories emerge within a research program as the result of the addition of auxiliary hypotheses to the predecessor theory. Lakatos calls the progression from a theory to its successor a problemshift . A research program is theoretically progressive if each problemshift in the series results (1) in excess empirical content relative to the unrefuted content of the predecessor and (2) predicts some novel fact. A research program is empirically progressive if the excess content of each successor theory leads to the actual discovery of a new fact. A research program is progressive simpliciter if it is both empirically and theoretically progressive.

Degenerative research programs, in contrast, are empirically or theoretically degenerative or both. Specifically, degenerative research programs involve problemshifts where the successor theory differs from the predecessor by the addition of ad hoc auxiliary hypotheses. An auxiliary hypothesis can be ad hoc in three ways: First, ad hoc1 , an auxiliary hypothesis can fail to result in excess content for the successor over the predecessor. Second, ad hoc2 , an auxiliary hypothesis can predict novel facts, but fail to receive empirical corroboration of those facts. Third, ad hoc3 , an auxiliary hypothesis may lead to corroborated predictions of new facts, but result in the research program's being an "...arbitrary series of disconnected theories." ( Lakatos 1978, p.88)

Whether or not one accepts a hard line Lakatosian criterion for evaluating research programs, the underlying intuition looks quite sound.3 In the quest for knowledge (or the definition thereof), a researcher must decide if a particular research program looks promising. One can think of doing research within a particular research program as betting on a horse. If one notices that the horse has won race after race and has posted faster and faster times, betting on that horse looks like a good idea. If, on the other hand, the horse posts several loses and has started to limp towards the finish, betting on that horse looks foolish. In this section I argue that the causal strategy has turned up lame.

If one looks at Goldman's 1967 theory as a problemshift with respect to a simple causal theory (as outlined in section 2), one notices that Goldman has introduced a number of auxiliary hypotheses to deal with the Gettier cases (as well as others). For instance, Goldman requires that one infer inferential empirical knowledge only from true beliefs, and that the inferences reconstruct all the "important links" in the causal chain from the fact that s is F to the evidence that s is F. (1967, pp.363 and 369-70) Goldman also asserts that "if x is logically related to y and if y is the cause of z, then x is the cause of z." (1967, p.368) Both the above-mentioned reconstruction and logical relation hypotheses are clearly ad hoc. Let us consider each of these hypotheses in the context of the problems to which Goldman applies them:

When discussing whether or not Goldman's 1967 theory captures the necessary conditions for knowledge, I point to several cases--like the edge and stair cases--in which the system makes an inference to a belief based upon a reliable indicator. I call such cases reliable correlation cases. Since these cases involve inference from evidence, Goldman's only means of addressing reliable correlation cases is his reconstruction hypothesis. The reconstruction hypothesis requires that one infer inferential knowledge from only true beliefs, and that the inferences reconstruct all the "important links" in the causal chain from the fact that s is F to the evidence that s is F. (1967, pp.363 and 369-70) The idea here is that one does not know that s is F based upon evidence unless one can correctly reconstruct through inference the causal chain from s's being F to the evidence upon which one bases the knowledge claim. Goldman wishes to use the recon struction hypothesis to distinguish between legitimate and illegitimate uses of evidence. His claim is that the only permissible evidential relationship is the actual causal chain between the fact and the evidence: A knower must be cognizant of the evidential relationship, i.e., the causal chain, in order to know something based upon evidence.

Note first, that Goldman's reconstruction hypothesis requires a causal chain from the fact known to the evidence. The relationship in these cases between a reliable indicator (the evidence) and the fact is not causal. Since the relationship between indicator and fact need not be causal, the reconstruction hypothesis fails to address reliable correlation. As Goldman's reconstruction hypothesis is Goldman's only means of addressing the reliable correlation cases, such cases resist his analysis.

Moreover, Goldman's reconstruction hypothesis has problems assimilating other cases of inference. Goldman's reconstruction hypothesis turns upon the notion of inferentially reconstructing the "important links" in a causal chain. One cannot tell if the target belief counts as knowledge, given some inferential reconstruction of a causal chain, until one determines that all of the important links have been included. Unfortunately, the hypotheses makes no predictions as to what counts as important links. Goldman himself comments that

Clearly we cannot require someone to reconstruct every detail, since this would involve knowledge of minute physical phenomena, for example, of which we are unaware. On the other hand, it is difficult to give criteria to identify which details, in general, are "important." This will vary substantially from case to case. (1967, p.363)

As a result of the above mentioned flaw, Goldman's theory cannot be said to predict which cases of belief based upon evidence count as knowledge any more than Ptolemaic astronomy could predict the motion of novel planets.

Goldman's reconstruction hypothesis also suggests a novel prediction concerning the thought processes of a person who has knowledge. Goldman's reconstruction hypothesis suggests that in all cases of inferential empirical knowledge, the cognizer reconstructs the causal chain from the fact believed to the evidence. The thought process prediction suggested by the reconstruction hypothesis, however, would appear eminently refutable. It seems more than sufficient for me to know that there is a fire in my neighborhood if I infer that fact from the heard sound of a fire engine. It seems unlikely and unnecessary that I reconstruct the causal chain from the fire to the report to the dispatch to my hearing the engine (my evidence). Likewise, it seems improbable and unnecessary that I inferentially reconstruct the causal chain from Larry Laudan 's writing of Progress and its Problems, to its publication and distribution, to my purchasing it, to my reading a passage in order to know that Larry Laudan held that an ad hoc successor is preferable to its predecessor.

Goldman introduces the logical relation hypothesis to deal with, among other things, knowledge of generalizations and universal laws. According to Goldman's account, the truth of generalizations and universal laws must cause one's knowledge of such generalizations and universal laws. So, for instance, one's belief that the period of the swing of a pendulum varies directly with the length of the pendulum arm must be caused by the fact that all of the periods of all the swings of all of the pendulums vary directly with the length of the arms. How can these general truths cause one to believe them? According to Goldman, "if x is logically related to y and if y is the cause of z, then x is the cause of z." (1967, p.368)

Of course, "logically related" is so vague that the principle is virtually useless. All the same, the logical relation hypothesis constitutes Goldman's only attempt to explain knowledge of generalizations and universal laws. Therefore, I propose to use it in the same spirit as Goldman.

If one tell's Goldman's story, the pendulum law is logically related to each instance of pendulum swing. The pendulums one studies causes one to believe the pendulum law. Hence, by Goldman's principle, the truth of the pendulum law causes one to believe the pendulum law. Yet, this story cannot be right. One comes to believe the pendulum law because of the cases one considers. In fact, one would have come to believe the pendulum law based upon those cases regardless of the truth of the pendulum law. This last observation, of course, is the infamous underdetermination of theory by data.

So, Goldman's logical relation hypothesis looks implausible: The instances one observes and not the truth of the pendulum law cause one's belief in that law. The observed instances are both necessary and sufficient to cause one's belief, while the truth of the pendulum law is neither necessary nor sufficient. One will, in other words, believe the law based upon the instances regardless of its truth; that is what makes science challenging.

But, one can find still another reason to question Goldman's logical relation hypothesis. Goldman's logical relation hypothesis entails an extremely implausible notion of causation. The fact that it is either raining or not raining is a logical consequence of the pendulum law. Since the raining disjunction is logically related to the pendulum law, the fact that it is either raining or not is a cause of my belief in the pendulum law according to Goldman's logical relation hypothesis. The fact that it is either raining or not clearly has not caused my belief in the pendulum law. Goldman's logical relation hypothesis clearly engenders a false theory of causality.