Often we cannot come up with the right word for an idea because we don’t have a firm grasp on the idea itself.

I may be able to come up with scads of words that accurately convey those ideas to you, but all those words do is reveal the state of my mind.

They deal with subjective reality, not objective reality.

but it is the statement that logic starts with,

Don’t assume your audience understands your meaning if you don’t make it explicit.

Speak in complete sentences.

True statements of objective fact are not open to argument; evaluative statements are.

If I want an evaluative statement to be accepted, I must argue for it.

avoid double negatives.

The two extremes to be avoided are talking down to people and talking over their heads.

An important point to note here is that we obviously cannot attune our language to our audience if we do not know our audience.

Avoid Vague and Ambiguous Language

A word is vague if its referent is blurred. We do not know precisely what the word is pointing to.

As a rule, the more general the word, the vaguer it is.

An ambiguous term (“equivocal,”

is one which has more than a single meaning

Location: 378

Avoid Evasive Language

The whole purpose of reasoning, of logic, is to arrive at the truth of things.

Something is said to be ontologically true, then, if it actually exists; it has real being.

Logical truth is simply the truth of statements. More broadly, we could say that it is truth as it manifests itself in our thinking and language.

What a true statement does is declare, through the medium of language, a correspondence

between ideas in the mind (subjective facts) and real states of affairs in the world (objective facts).

What determines the truth or falsity of a statement is what actually exists in the real world. Logical truth, in other words, is founded upon ontological truth.

I have no doubts about an actually existing situation in the real world, but in my statement about that situation I consciously and deliberately contradict my own knowledge.

“correspondence theory of truth.”

The coherence theory of truth maintains that any given statement is true if it harmoniously fits into (is coherent with) an already established theory or system of thought.

We should be aware, though, that the coherence theory of truth can be seriously abused,

This being so, the terms “the first principles of logic” and “the first principles of human reason” can be said to refer to the same thing.

THE PRINCIPLE OF IDENTITY Stated: A thing is what it is.

Sometimes we entertain contradictions without realizing that they are such, because we are ignorant of the relevant objective facts.

Rationalization is reasoning in the service of falsehood.

(The principle is this: A negative can only be recognized as a negative—“uncertainty”—because its positive opposite is already known.)

A proficient principal cause can do things with even inferior instruments that an incompetent principal cause couldn’t do with even the best of instruments.

The specific difference is the characteristic (or characteristics) that sets apart the object we want to define from other objects in its genus.

whenever we have real certitude, we should express that certitude by speaking categorically.

It reveals what is subjectively the case,

because it declares what is, in fact, the speaker’s opinion.

Some people deliberately leave out linguistic qualifiers (“all,” “some”) because they want what they are saying to be understood as applying to an entire class without being explicit about it.

True, he didn’t say it, but he implied it.

So long as the entire class is not being referred to, the statement is particular.

Always be as precise in your statements about things as your knowledge of them allows you to be.

a “premise” statement and a “conclusion” statement.

It is rare to have multiple conclusions to an argument. And, in fact, they are to be avoided. A single conclusion is always best.

This is just another way of saying that the most effective arguments are those that are trying to make a single point.

Common logical indicators for premises are “because,” “since,” “on account of.” Common logical indicators for conclusions are “therefore,” “thus,” “so.”

The premise is the foundation of an argument.

follow necessarily. A “necessary conclusion” is one that it is not possible to doubt—it is certain.

Knowledge of a part does not allow me to say anything definitive about the whole.

It is a pretty obvious mistake to claim that something is necessarily true for a whole group because it happens to be true for a part of the group.

It easily qualifies as one of the human family’s favorite fallacies.

Ideas belong together if their grammatical connection reflects a real connection in the objective order of things.

All things being equal, if the same idea can be communicated both affirmatively and negatively, it is better to opt for the affirmative construction.

A judgment is sound to the extent that the relationship it forges between two ideas reflects a real relationship in the objective world.

One of the most common arguments based on comparison is called “the argument by analogy.” (An analogy is a relation of similarity between two things.)

First, truth has to do only with statements, whereas validity has to do only with that structural arrangement of statements that we call an argument.

Second, a statement is true if what it asserts reflects what is objectively the case. An argument is valid, to echo what was just said, if its structure is such that it will ensure a

true conclusion—if its premises are true.

syllogism, the argument that represents the most finished form of reasoning.

The first statement is called the “antecedent”; the second is called the “consequent.” “A → B”

Seldom is it the case that there is a real necessary connection between antecedent and consequent in our arguments. The result of this is that the conclusions we reach in our arguments do not necessarily follow.

In the vast majority of

conditional arguments we use, our conclusions will be probable ones.

Here is a syllogistic argument in partially symbolic form: Every M is P Every S is M Therefore, every S is P

Validity is not enough.

“Musicians are superior people.” This is a statement not of fact but of value.

The conventional way of distinguishing between deductive argument and inductive argument is to say that the former starts from the general and proceeds to the particular, while the latter starts from the particular and proceeds to the general.

argument is productive of necessary conclusions, while inductive argument has the capacity to produce probable conclusions only.

We could say that deductive argument is analytic because it breaks a general truth down into its constituent parts.

An unsupported statement is a mere opinion, which we are free to take or leave at face value.

A distinction has to be made between skepticism as a permanent attitude, which is to be avoided at all costs, and skepticism as a fitting, even necessary, response to a particular situation.

An agnostic is someone who maintains that he lacks enough knowledge regarding a particular issue to be able to make a definite judgment about it.

Such ignorance is the result of indifference or laziness.

A cynic is someone who makes emphatically negative estimates without sufficient evidence. A naïve optimist is someone who makes emphatically positive estimates without sufficient evidence.

prejudice (the word comes from the Latin praejudicare, “to judge beforehand”),

A narrow-minded person refuses to consider certain alternatives only because they do not meet his prejudiced assumptions about what is and is not worth pursuing.

G. K. Chesterton pointedly observed that an open mind,

like an open mouth, should eventually close on something.

The more intense our emotional state, the more difficult it is to think clearly and behave temperately.

Never appeal directly to people’s emotions.

Do not waste time and energy trying to argue with people who will not or cannot argue.

Sincerity is a necessary condition for sound reasoning but not a sufficient one.

The principal explanation for this is that a favorite tactic of fallacious reasoning is to circumvent sound reasoning by appealing directly to the emotions.

Remember, this is an invalid argument because the conclusion does not follow necessarily.

“undistributed middle term.” A less technical name given to this fallacy is “guilt by association.”

An equivocal term or word has more than a single meaning.

The reason is that it lacks real premises—information that offers genuine support for the conclusion.

The very point that has to be proved to be true is simply assumed to be true.

A variation of the begging-the-question fallacy is “arguing in a circle,” sometimes called the “vicious circle.”

Rule of thumb: Make as few assumptions as possible.

To repeat an important rule: In argumentation we respond to the argument, not to the person behind the argument.

The essence of the fallacy you committed is this: Knowing a source to be generally bad, you assume that everything coming from that source must necessarily be bad. This doesn’t follow.

It is not enough to take things apart; we have to put them back together again.

fallacy of “reductionism.” This fallacy is committed when we selectively focus on only some of the parts of a composed whole.

We misclassify things because we fail to properly identify them in the first place, and we do that because we are not paying attention.

The “red-herring fallacy” provides us with another example of this tactic. It introduces emotionally volatile information which is deliberately calculated to agitate a specific audience. Two things make this tactic fallacious: First, it is a direct appeal to emotion, not reason; second, the information introduced has nothing at all to do with the issues being dealt with in the argument.

An Inability to Disprove Does Not Prove

I commit the fallacy of the false dilemma when, in a situation entailing several possibilities, I attempt to persuade you that there are only two.

The fallacy of post hoc ergo propter hoc is committed when, in response to a situation where a certain event A happens, followed by another event B, we decide, solely on the basis of A having come before B, that A caused B.