“It is no wonder that the critic has a problem making up his mind about hats and the RazorsKiss does not appear to be razor sharp.”
– Mark
“They [Mr. Di Giacomo’s posts] are thorough, clear, correct and easily understood. At least if one is willing to wipe the tears away and quit whining.
Cheers”
– Mark
“If Then” Statements and Modus Tollens
Someone named Mark, commenting on Mr. Di Giacomo’s most recent blog post found here writes, “TAG is a very simple if / then. It doesn’t require much of an argument to show that, just the short demonstration given above.”
I am not sure where anyone denied that TAG is a “simple if / then,” but I have not. I do believe that TAG takes the form ‘If p then q (Where q is the precondition of p.)’ The implication in the above statement is neither inductive nor deductive. Bahnsen says as much in his lectures. Thus I do believe also that TAG is neither deductive nor inductive (as Bahnsen also states in his lectures). Mark has apparently taken ‘If p then q’ to be a deductive argument. While ‘If p then q’ is a conditional statement it is not necessarily part of a deductive argument.
Recall that in my other posts I have repeatedly asked for an example of Bahnsen explicitly stating that TAG is deductive. Aside from the claim that Bahnsen used modus tollens in his debates I have not received any other response. To be fair there has been a bit of mockery and charges that I have sinned but so far there has not been a single example of where Bahnsen states that TAG is deductive. What about the argument Bahnsen used in his debates? Well, let us take a look at how Bahnsen stated his argument in his debate with Stein. At the end of his Opening Statement, Bahnsen says, “The transcendental proof for God’s existence is that without Him it is impossible to prove anything.” (http://www.bellevuechristian.org/faculty/dribera/htdocs/PDFs/Apol_Bahnsen_Stein_Debate_Transcript.pdf) Is this modus tollens? Let us take a look:
If P, then Q.
¬Q
Therefore, ¬P.
It is safe to say that if someone were to write out Bahnsen’s statement as an example of modus tollens on a logic exam that person would not get that question right. Bahnsen does not state the conditional that Mark claims constitutes a deductive argument. Even if Bahnsen had stated the conditional (Perhaps “If God does not exist then it is impossible to prove anything” would fit the conditional better than “If anything can be proven then God exists”.) then it would not have constituted a deductive argument and still would have fit perfectly with what I wrote in the beginning of this post. So not only has no implicit use of deduction by Bahnsen been provided but neither has an explicit statement by Bahnsen that TAG is a deductive argument been provided. The latter is what I would really like to see. If I am wrong I want to know that I am wrong and I want to know why I am wrong. I have already presented quotations from Bahnsen where he explicitly denies that TAG is deductive and have explained in my posts why Mr. Di Giacomo’s attempted explanations of those quotations in accordance with his position that TAG is deductive do not work.
My Argument from the Text
“To put it simply, in the case of ‘direct’ arguments (whether rational or empirical), the negation of one of their premises changes the truth or reliability of their conclusion. But this is not true of transcendental arguments, and that sets them off from the other kinds of proof or analysis. A transcendental argument begins with any item of experience or belief whatsoever and proceeds, by critical analysis, to ask what conditions (or what other beliefs) would need to be true in order for that original experience or belief to make sense, be meaningful, or be intelligible to us. Now then, if we should go back and negate the statement of that original belief (or consider a contrary experience), the transcendental analysis (if originally cogent or sound) would nevertheless reach the very same conclusion.” (Bahnsen, Van Til’s Apologetic, 501-502.)
Mark writes:
“Additionally Mr. Choosing Hats isn’t particularly astute. He imagines that the inclusion of the two sentences to the Bahnsen quote somehow validates his argument. i.e.
To put it simply, in the case of ‘direct’ arguments, whether rational or empirical, the negation of one of their premises changes the truth or reliability of their conclusion. But this is not true of transcendental arguments, and that sets them off from the other kinds of proof or analysis.”
While I originally thought that Mr. Di Giacomo might have mistakenly cut these two lines off of the Bahnsen quote I was later found to be mistaken since he did so even after I pointed out in one of my responses that he had done so. There is also the possibility that he did not ever read my responses. Suffice it to say that I do believe the two lines to be extremely important to the meaning of the quote and that is why they are provided with it. Mark has attempted to explain these two lines in light of the position that TAG is deductive (which I welcome):
“NB that choosing hats errantly supposes that by rational Bahnsen means deductive. But anyone with even a modicum of familiarity with Bahnsen and Van Til would know that both of them considered induction rational.
Mark believes that I err in thinking “that by rational Bahnsen means deductive.” Note that Bahnsen mentions two type of “direct arguments” which are “rational” and “empirical.” Direct arguments are set in opposition to transcendental arguments. The two types of direct arguments are “rational” and “empirical.” When Bahnsen writes, “whether rational or empirical” he shows that he understands the two as being different types of arguments by his use of “whether” and “or”. Rational arguments are not the same as empirical arguments in the way Bahnsen is using the terms here. Now what might these two different types of arguments be? What Bahnsen writes next is that “the negation of one of their premises changes the truth or reliability of their conclusion.” Note that the use of “truth or reliability” parallels Bahnsen’s earlier use of “rational or empirical.” We may therefore link “truth” with “rational” and “reliability” with “empirical.” I will return to this in a moment. Let us take a few commonplace understandings from the history of philosophy which Bahnsen was well acquainted with and see if they assist us in understanding what Bahnsen means in this quote. Typically “rationalism” and “rational” are associated with deduction. It is also the case that “empiricism” and “empirical” are typically associated with induction. Finally, deduction and induction are often taken to be “the two” main kinds of argumentation. Recall what was mentioned just a moment ago about the parallel between “truth” and “rational” and “reliability” and “empirical.” Bahnsen states that “the negation of one of their premises changes the truth or reliability of their conclusion.” Again I suggest that “truth or reliability” refers to “rational or empirical” respectively. Thus the negation of one premise of a deductive argument changes the truth of the conclusion of the deductive argument. There is only one way to change the truth of the conclusion of an argument and that is to change the conclusion so that it is false. If the conclusion of an argument is false it is not reliable at all and thus the result of the reliability of the conclusion being changed cannot refer to the type of argument that Bahnsen has in mind at this point. The negation of one premise of an inductive argument changes the reliability of the conclusion of the inductive argument however the conclusion can still remain true and thus the result of the truth of the conclusion being changed cannot refer to the type of argument that Bahnsen has in mind at this point. Therefore I take Bahnsen to be equating “rational” with “deductive” and I believe I do so upon sound exegesis of the text in question.
Mark’s Argument from the Text
Mark claims, “But anyone with even a modicum of familiarity with Bahnsen and Van Til would know that both of them considered induction rational.” While I am surely no expert I should like to think that I have at least “a modicum of familiarity” with the two apologists mentioned. They did consider induction to be rational but in stating this I would contend that we are using “rational” in a wholly different manner than the way we used it before. While I am certainly open to correction I believe that Mark is thinking of “rational” here as opposed to “irrational.” But observe that when “rational” is taken this way we might just as easily state that “anyone with even a modicum of familiarity with Bahnsen and Van Til would know that both of them considered [deduction] rational.” Would Mark object to this statement? It is doubtful that he would. Even given Mark’s explanation then one might take “rational” to refer to either induction or deduction. The meaning of the word must be interpreted according to its context. My interpretation is above. Now I would like to take Mark’s explanation of the passage and see if it makes sense of what the passage actually says.
“To put it simply, in the case of ‘direct’ arguments, whether rational or empirical, the negation of one of their premises changes the truth or reliability of their conclusion. But this is not true of transcendental arguments, and that sets them off from the other kinds of proof or analysis.”
Mark apparently thinks that we need to take Bahnsen’s use of “rational” here to refer to induction since he has written that “anyone with even a modicum of familiarity with Bahnsen and Van Til would know that both of them considered induction rational.” The trouble with this interpretation is that Bahnsen is speaking of at least two kinds of direct arguments. Note the plural in his use of “arguments”, “their”, “their”, “them”, and “kinds”. Someone might object that Bahnsen also speaks of transcendental arguments in the plural. My response is twofold. First, there are different kinds of transcendental arguments. For example, TAG is significantly different from many other transcendental arguments. However transcendental arguments still share in common the feature that they are transcendental. Second, the use of the plural does not alone prove that Bahnsen is speaking of at least two kinds of direct arguments but does add inductive force to my earlier argument from Bahnsen’s use of “whether rational or empirical” which denotes that two different kinds of direct arguments are in view. Bahnsen further speaks of transcendental arguments being set off from “the other kinds of proof or analysis” and this certainly entails that there is more than one kind of argument being contrasted with transcendental arguments. However if Bahnsen is writing about more than one kind of argument and “rational” refers to “inductive” argumentation then what does “empirical” refer to? If “empirical” refers to deduction then we have the problem of counter-intuitively linking terms together and my claim that deduction is being contrasted with TAG is still provable from the text anyway (because it will not matter which term refers to deduction as long as one does). If “empirical” refers to induction then we have the problem of explaining the plurality just mentioned. While there may be some other problems with Mark’s interpretation I will mention only one more.
Mark claims “that choosing hats errantly supposes that by rational Bahnsen means deductive.” However his objection has no bearing upon my explanation of the text as teaching that deduction and TAG are two different types of arguments. Instead of supposing that by “rational” Bahnsen means “deductive” let us just do away with that part altogether and see what happens.
“To put it simply, in the case of ‘direct’ arguments…the negation of one of their premises changes the truth or reliability of their conclusion.”
Now I can no longer take “rational” in the passage to refer to “deduction” because it is no longer in the passage. Bahnsen explains in the quotation that “direct arguments” have the feature that “the negation of one of their premises changes the truth or reliability of their conclusion.” Now is it true of any given deductive argument that negating one of its premises “changes the truth or reliability of [its] conclusion?” The answer is undoubtedly “Yes.” Therefore even if Mark’s comment were true it would not affect my understanding of the text. Bahnsen then writes that, “this is not true of transcendental arguments, and that sets them off from the other kinds of proof or analysis.” That is, TAG is not a deductive argument. I do not know how much clearer Bahnsen could have been on this point.
Mark continues:
“Second he says he thinks his clarifying quote shows that TAG is not deductive. This is absurd.”
While I have stated that the quotation shows that TAG as Bahnsen understood it is not deductive it is also true that I have actually argued from the text that the quotation shows such. Mark is welcome to engage my explanation of the text provided above in light of his complaints and he is welcome to attempt to save his own explanation of the text in light of mine. I do not believe that my statement or supporting argumentation is absurd but if it is I certainly want to know why it is absurd. The comment box here is open, I am ready and willing to discuss the text, and I will gladly welcome correction in my understanding of Bahnsen’s presentation of TAG.
Mark explains, “All it shows is that TAG does not suffer from alternative major premises for there is only one which is stated by Bahnsen immediately after Mr. choosing hats imagined defeater.” He then quotes Bahnsen again and emphasizes the part of the quotation which states that a transcendental argument “begins with any item of experience or belief whatsoever.” Bahnsen is not writing about “alternative major premises.” Bahnsen is writing about going back and negating a premise. When you do this with a deductive or inductive argument it will change the truth or reliability of the conclusion respectively. Bahnsen states that this is not the case with transcendental arguments. If Mark means something more here then he may need to explain it in greater detail or provide some examples. Until then it is my position that Mark’s attempt to explain the passage from Bahnsen in light of his agreement with Mr. Di Giacomo that TAG is deductive fails. Hopefully Mark will respond to my exposition of the text and not merely accuse me of sinning because I disagree with him or make other unflattering comments about me as doing so would not constitute an actual answer and it would not go very far in persuading me that I have been mistaken in my understanding of these matters.
TAG, Deduction, and Certainty
It should be pointed out that the post that Mark’s comment appears on has been brought to my attention several times as being a response directed toward what I have been posting. So far as I can tell it is directed at the following argument I made in the comments section on my original post about this subject:
Another problem with claiming that TAG is a deductive argument:
1. If TAG is a deductive argument then it does not provide certainty.
2. TAG provides certainty.
3. Therefore TAG is not a deductive argument.
The first premise is supported by Greg Bahnsen’s claim and argument in his debate with R.C. Sproul that deductive arguments do not provide certainty.
The second premise is supported by Greg Bahnsen’s claim and argument in the same debate with R.C. Sproul that TAG provides certainty.
Therefore TAG is not a deductive argument. This is just one way of establishing my point which I mentioned at the end of my response to Mr. Di Giacomo though not in this form.
Mr. Di Giacomo appears to concede in his post that deduction does not provide certainty. However his reasons for thinking that deduction does not provide certainty differ from Bahnsen’s reasons which are relevant to this discussion. Bahnsen was concerned with the formal aspects of deductive arguments and not the truth or falsehood of their premises which Sproul had already addressed. Thus if TAG is formally deductive it cannot provide certainty. Yet Bahnsen claimed that TAG does provide certainty. This is not to deny the roles of the Word of God and the Holy Spirit.
The Fallacy Of False Antithesis
The only line I can find where I think that Mr. Di Giacomo has attempted to explain the text I am about to quote again is when he writes, “Bahnsen typically employed modus tollens (MT) in his formal argument, yet he distinguished his employment of TAG from deduction.” Is modus tollens deduction? Yes. Is TAG modus tollens? According to Mr. Di Giacomo, yes. Therefore according to Mr. Di Giacomo TAG is deduction. Yet according to Mr. Di Giacomo the following is also true: Bahnsen distinguished TAG from deduction. How can someone distinguish deduction from itself? Since I do not have an answer to this question I am completely unsure of what Mr. Di Giacomo means. An argument is either deductive or not deductive and it is a matter of fact that modus tollens is a deductive argument.
I believe that the error people are inclined to make while discussing this topic has been pointed out by Van Til and Bahnsen.
“Years ago Van Til realized that opponents of presuppositionalism tend to think that there are only two kinds of reasoning: inductive and deductive. Deductive reasoning stands opposed to inductive. However, there is also transcendental reasoning, in which the preconditions for the intelligibility of what is experienced, asserted, or argued are posed or sought. It, too, stands opposed to a purely inductive approach to knowledge. Critics seem to think that, since presuppositionalism does not endorse pure inductivism, it must favor deductivism instead. This logical fallacy is known as false antithesis.” (Bahnsen, Van Til’s Apologetic, 176, n. 55.)
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