In 1931 a late nineteenth and early twentieth century philosopher at Oxford by the name of H.W.B. Joseph published a book called Some Problems in Ethics. The following is quoted from the aforementioned work:
If thought is laryngeal motion, how should any one think more truly than the wind blows? All movements of bodies are equally necessary, but they cannot be discriminated as true and false. It seems as nonsensical to call a movement true as a flavor purple or a sound avaricious. But what is obvious when thought is said to be a certain bodily movement seems equally to follow from its being the effect of one. Thought called knowledge and thought called error are both necessary results of states of brain. These states are necessary results of other bodily states. All the bodily states are equally real, and so are the different thoughts; but by what right can I hold that my thought is knowledge of what is real in bodies? For to hold so is but another thought, an effect of real bodily movements like the rest….These arguments, however, of mine, if the principles of scientific [naturalism]…are to stand unchallenged, are themselves no more than happenings in a mind, results of bodily movements; that you or I think them sound, or think them unsound, is but another such happening; that we think them no more than another such happening is itself but yet another such. And it may be said of any ground on which we may attempt to stand as true, Labitur et labetur in omne volubilis aevum [“It flows and will flow swirling on forever” (Horace, Epistles, I, 2, 43)].
Joseph is not likely suggesting that thought might pertain to the larynx. Much as the larynx is involved in producing sound it might be posited that other physical entities that are like the larynx are likewise involved in the production of thought (with the qualification that thought is wholly contingent upon whatever the entity may be which is used to complete Joseph’s illustration). If it is the case that thought is as Joseph has hypothesized for the sake of argument then an appropriate question is “how should any one think more truly than the wind blows?” The question implies that there is an obvious problem with not being able to think “more truly than the wind blows” and is followed by Joseph’s reasons for raising the question.
Given a host of generally accepted assumptions concerning the world and especially those typically accepted by the naturalist all “movements of bodies are equally necessary” which is to say that every movement of every physical entity is in some way causally connected to another and hence is determined. This is just as true for one movement of one physical entity as it is for a movement of a wholly different entity. There are a multitude of problems with this view of the universe that will be set aside in order to focus upon what more directly pertains to the current argument.
The movements of bodies described by Joseph “cannot be discriminated as true and false.” The reason Joseph has for claiming that it is impossible to evaluate the movements of bodies as true or false is that doing so constitutes a category error. A category error is when some property is attributed to an entity which cannot possess that property. A category error denotes an absurdity. Joseph provides two examples of category errors. One example of a category error is calling “a flavor purple.” It is logically impossible for flavor to posses the property of color as flavor and color belong to two different classes. Since purple is a color it cannot be predicated of flavor. Likewise it is “nonsensical to call…a sound avaricious.” Joseph suggests that it seems every bit as nonsensical “to call a movement true.” Truth and falsehood are not predicated of the movements of bodies; affirming that they are is a rather simple mistake in categorization.
The category error may be set aside in order to look at the view in question more closely. If thought is nothing more than a bodily movement then the thought that thought is a bodily movement (and its consequential thoughts) is also the result of a bodily movement. Joseph writes, “Thought called knowledge and thought called error are both necessary results of states of brain.” What we allegedly know and what we allegedly get wrong are “necessary results of states of brain” because as stated earlier all “movements of bodies are equally necessary.” The state of the brain labeled ‘knowledge’ is in this sense no different from the state of the brain called ‘error’. Both of these states of the brain are the result of the movement of bodies and both are determined because they are the result of the movement of bodies.
These states are necessary results of other bodily states. All the bodily states are equally real, and so are the different thoughts…
It is justifiable to inquire as to why these states of the brain should be referred to in the plural ‘both’ and ‘states’ if they are essentially the same. The only difference between a state of brain called knowledge and a state of brain called error seems to be our labeling them such, but such labeling is at best arbitrary and at worst unnecessary since there is no need for two allegedly antithetical labels denoting the same thing.
Joseph raises a different question when he asks, “by what right can I hold that my thought is knowledge of what is real in bodies?” By “right” Joseph alludes to the justificatory element of knowledge which is by now being called into serious question given the truth of the position Joseph is assuming for the sake of argument. It might very well be that all of the talk of knowledge concerning bodies, movement, and truth are actually error. One should not think of error here as being the sort of error which almost every person readily accepts as possible. The recognition that alleged knowledge concerning bodies, movement, and truth might actually be error – the recognition that people can and often do make mistakes concerning what they think of these things – is uninteresting and beside the point. Likewise surface-level explanations or instances of some action being carried through do not constitute a response to the sort of problem Joseph is pointing out.
The sceptic is not interested in being told that if he wishes to test my claim to such and such an effect, he can go and look, or feel, or test-drive one himself; he will simply say that doing all that is not to the point. The problem is rather, in the case of any claim we care to make about the way things are in the world, what at bottom justifies us in believing what we are committed to in making such a claim?
Joseph is inquiring as to the justification for the belief that “thought is knowledge of what is real” because this belief “is but another thought, an effect of real bodily movements like the rest.”
Joseph’s final thoughts on this topic are rather weighty ones that the naturalist must consider and answer satisfactorily if he or she is going to be taken seriously. He closes the reductio ad absurdum by applying the argument to his own thought given the truth of naturalism granted for the sake of argument.
These arguments, however, of mine, if the principles of scientific [naturalism]…are to stand unchallenged, are themselves no more than happenings in a mind, results of bodily movements; that you or I think them sound, or think them unsound, is but another such happening; that we think them no more than another such happening is itself but yet another such. And it may be said of any ground on which we may attempt to stand as true, Labitur et labetur in omne volubilis aevum [“It flows and will flow swirling on forever” (Horace, Epistles, I, 2, 43)].
There have been some discussions in contemporary philosophy regarding how the argument is to best be expressed given the infinite regress Joseph alludes to in the final lines of the quotation above that will have to be set aside for another time. What Joseph has shown if his argument is successful is that given what people typically believe quite strongly regarding such notions as truth, falsehood, knowledge, error, rationality, etc. those positions which accept what Joseph has written concerning the nature of reality as a whole and hence thought itself are necessarily false. The argument is a primitive one which leaves much to be said, but it is the beginning of an extremely strong philosophical argument against naturalism and has a transcendental quality about it. Given the possibility of the intelligibility of human experience naturalism is false and questions about what view does provide for the preconditions of intelligible human experience are raised for the adherent to such a position as naturalism.
 Joseph, H.W.B. Some Problems in Ethics. Oxford University Press, 1931, pp. 14-15 as quoted in Kreeft, Peter; Ronald K. Tacelli. Handbook of Christian Apologetics: Hundreds of Answers to Crucial Questions. Press Downers Grove, Illinois: InterVarsity, 1994, pg. 67.
 Grayling, A.C. The Refutation of Scepticism. La Salle, Illinois: Open Court Publishing Company, 1985, pg. 6.