The Free Radical Online - Perigo vs. Nola

Round One: Robert Nola Responds

Today some person pinned on my University door a copy of an article from the journal Free Radical, entitled 'Objective Philosophy' [TFR #30] by Lindsay Perigo. In it I am reported as having said: 'logic has nothing to do with reality'. Also, despite knowing nothing of my views on the matter, I am falsely castigated for being part of a long tradition of subjectivism in philosophy. Much of the philosophical part of the article is confused and confusing. So let us concentrate on the claim: 'logic has nothing to do with reality'. First define the terms in the claim. What is meant by 'logic' and 'reality'? In one standard sense, the word 'logic' is used to refer to the valid rules of argument employed in reasoning of the sort discussed in logic text-books; examples of these rules are the Law of Excluded Middle, Modus Ponens, etc. As for 'reality' many things can be meant by this. So give it what meaning you like. For the purposes of this discussion I will take it to mean the entire history of the world from the big bang (assuming it did occur), to the formation of the Solar system, the evolution of life on Earth, and so on, up to our present day. All that seems real enough and would, I hope, be agreed to by a supporter of Ayn Rand's Objectivism.

Now what has logic to do with reality, as defined? Much turns on the way in which the phrase 'to do with' might be taken. But first, some points about logic.

Valid arguments contain component statements which occur either as premises or as conclusions. About these let us say the following: the component statements are true if and only if they correspond to reality — otherwise they are false. Now one of the first things one learns about deductive reasoning is the following. In a valid argument it is possible that (1) the premises be true and the conclusion true; (2) the premises be false (or mixed true/false) and the conclusion false; (3) the premises be false (or mixed true/false) and the conclusion true. What is not possible is that, in a valid argument, (4) the premises be true and the conclusion false. These claims cannot be proven here; but they are a standard, important, matter to grasp concerning the elements of logic; they are set out in most first year logic texts. Of course, what we are interested in is case (1), the class of valid arguments from true premises; but this takes us outside the province of logic proper.

In the light of possibilities (2) and (3) the validity of the argument remains unaffected by whether the component statements are true or false, i.e., whether they are about reality or not. In a nutshell, we can argue validly about component statements all of which are false, as we can argue about entirely true component claims. In this sense the validity of the rules of logic has nothing to do with reality, i.e., the stock of true claims about the history of the world. More broadly, logical principles apply over an infinite number of 'possible worlds', that is, ways in which the actual world can be but is not.

However perhaps Mr Perigo has a quite different claim in mind, viz., 'logic has nothing to do with what we know about reality'. He says, just above his claim about myself, that his opponents hold the view that 'reason can't tell you what is true & false' (italics mine). In this context 'tell' and 'know' come to much the same thing. Now this second, quite different claim is false; and I do not endorse it. If some alleged rule of logic is up for consideration, then reason can tell us whether it is true or false. But confine ourselves to the way our world is. Logic, the employment of principles of reasoning, is quite intimately involved in telling us what reality is like, or in determining our knowledge of reality. However, though necessary, logic is not sufficient. We need much more than rules of inference; for example, we need to make observations and form hypotheses for test.

In sum, there are two quite distinct claims: (a) Logic is necessary (but not sufficient) for knowledge of reality; (b) Logical principles of reasoning are independent of the actual way the real world is (whether or not we can know, or can tell, how it is).

From the original disputed claim Mr Perigo appears to conclude: 'There is no reality' (see third column). However this conclusion does not follow. That logic is independent of reality does not entail that there is no reality. But perhaps he is attributing this view to his opponents. They are also said to argue as follows (see second column): from the premise 'reason can't tell you what is true & false' they are alleged to infer 'there is no true & false'. But Mr Perigo is being quite unfair to his opponents. It is quite correct to claim that reason cannot tell you, say, whether or not 157 cars passed your house in the last 24 hours; only observation, not reason, can tell us that. But it is a gross non sequitur to infer from this that there is no truth or falsity about the number of cars — even if we never find out what the number is.

It is good to be reminded that there are many matters which are objective and that not all is a matter of opinion, taste, faith or subjective experience. However this is objectivism with a little 'o' and not Objectivism which, like any system of thought, needs to be critically examined in case it be accepted dogmatically. For, given the above logical points, even false doctrines can entail some truths.

If you enjoyed this, why not subscribe?