The Colloquial Logic

**Irishman** · May 18, 2007, 04:57 PM

This thread is in response to the two threads entitled "Is belief in God Logical" and "Can Logic explain everything".

In these threads, there was a fundamental disagreement in the meaning of the term “logical”. Some people argued that Logic should be defined in its philosophical term, as a method of determining the validity and or strength of an argument.

In Philosophy there are two main types of logic; Deductive and Inductive Logic, which correspond to Deductive and Inductive arguments respectively. Should we say that a logical argument is a valid one?

If so, then this VALID argument would be logical,

P1. If the moon is made of cheese then Ice cream tastes good.
P2. The mood is made of cheese
C. Ice cream tastes good.

This argument is VALID. There is no possible situation in which the premises are both true and the conclusion is false. But one would say, “Well that is not a logical argument, you haven’t proven anything! But using our definition of Logic as a valid argument, “C” is logical! Because of this, we know that there is more (much more) to Logic than in the actual meaning.

Inductive logic, at the moment is much less scientific and its nature is open to interpretation, and I will speak more of this later.

If you ask why the above argument is not logical, how would the average person respond? Well, “The first premise and the second premise are false!” But the art of Logic tells us nothing of the soundness of an argument. There is no procedure in logic for assessing the truth value of the premises.

Using this average understanding of Logic, we must describe a logical statement or conclusion as one which is based on a SOUND argument, in other words a valid argument with true premises (which parts from formal logic.) This would seem to imply that “logical” does not have much to do with the actual process of Logic. Also I would like to note that the terms logical argument and illogical are not found in Logic. Logic only uses the terms invalid and valid.

Is this definition sufficient though? No. We must revisit the nature on inductive arguments. Ask an average person if this argument is logical,

P1. The thermostat reads 22 Degrees
P2. I am comfortable.
C. It is 22 degrees.

This argument would be described as logical, it would be logical to assume that it is 22 degrees in the room, BUT this is not a VALID argument. If the thermostat were off by one degree, the temp could be 23.

Thus we must include into our definition of Logic the inductive logic of probability.

Here we end with a definition of Logic which states, a claim or conclusion is “Logical” if the conclusion of the argument follows from the premises surely or to a high degree of certainty. In other words, a logical claim is one which you have used the rules and processes of reasoning to achieve, thus, “Logical” in colloquial meaning, is identical to rational; and logic to reason.

What do you think? I thought it would be helpful to have a unified definition of Logical to understand what these threads mean. Thus, threads like “Can logic explain everything” can be interpreted to mean “Can the rules of reason explain everything”. I feel that this will help to prevent some of the posts which claim that Logic cannot explain anything, as well this is technically correct (Logic on its own is useless) the common use (even in philosophy) of "Logic" is to be interpreted to mean "reason".

**~~enoch~~** · May 18, 2007, 05:00 PM

Originally Posted by wiki

Logic arose from a concern with correctness of argumentation. The conception of logic as the study of argument is historically fundamental, and was how the founders of distinct traditions of logic, namely Plato and Aristotle, conceived of logic.

Modern logicians usually wish to ensure that logic studies just those arguments that arise from appropriately general forms of inference; so for example the Stanford Encyclopedia of Philosophy says of logic that it "does not, however, cover good reasoning as a whole. That is the job of the theory of rationality.

Rather it deals with inferences whose validity can be traced back to the formal features of the representations that are involved in that inference, be they linguistic, mental, or other representations" (Hofweber 2004).

this is a pretty standard way of explaining what logic is
an approach to study, no more or less

**Irishman** · May 18, 2007, 05:05 PM

Hence the title "The Colloquial Logic".

I feel I aptly covered the fact that Logic in its most basic form covers only the form of arguments, But the entire point of my post was to show that in eceryday language with non-philisophically trained people, the term logic can be taken as rational.

Certainly you are not claiming that when an average person says an argument if Logical that they mean "The form of the argument is proper but I am not commenting on the truth value of the conclusion at this time!"

As I covered, Logic, in modern speach (in case you didn't know what colloquial means) can be used as reason.

**~~enoch~~** · May 18, 2007, 05:07 PM

I followed - I was adding to your basis to help avoid unneeded responses that did not follow

logic trifecta - logic is as false a god as all the others man worships without acknowledging the necessity of doubt inherent to the nature of wisdom