Being Logical
: A guide to good thinking by D.Q. McInerny Part 1--Preparing the mind for logicDeals with the proper frame of mind that must be established if logical thinking is to take place at all. 1. Be attentive
o Don’t skim situations, just because they are similar to others
Every situation is unique even if in a small way Be alert to uniqueness
2. Get the facts Straight
o A fact is something made or done
Has clear objective status that is independent of others
o 2 types of facts
Things
• Ex.: The White House
• To determine validity pay it a visit
o If it is a fact it must exist somewhere in some form
Events
• Made up of things or the actions of things • Ex.: Lincoln assassination
• To determine validity you must consult documents that account for it
o Objective
Things and Events
• They exist in the public domain • Principle access to all
o Subjective
Limited to the subject experiencing it • Indirect factualness
• Ex.: Pain
o Most facts must be indirectly experienced
Exercise care in established validity of indirect evidence 3. Ideas and the Objects of Ideas
o Every idea is a traceable thing
A subjective evocation of an objective fact
Clear ideas faithfully reflect the objective order they derive from Unclear distort the representation of their lineage
o Ideas are the means, not the end, of knowledge
Look through ideas to the objects they represent 4. Be Mindful of the Origins of Ideas
o People naturally favor their own ideas
• These are either objective facts or other ideas
o Determine validity by seeking out a relative example in external reality
Ex. Cats
Vs centaurs which don’t have an external example in the real world • Thus they are a subjective fact as they only exist in the mind 5. Match Ideas to Facts
o 3 basic components to human knowledge
Objective fact • Ex.: Cats The idea of cats
The word applied to the idea • Ex.: in English, “Cats”
o Simple idea
Direct correlation between idea and objective fact • Ex.: idea of cat
• Corresponding to idea of cat is an extramental world entity
o Clear, sound and corresponds to the real world
o Complex ideas
No simple one-to-one correspondence between idea and thing • Instead correspondence is one-to-many
If a complex idea is to be communicable to others it must refer to what is common to both you and others
• To prevent an idea from being pure subjectivism,
o you must continuously touch base with those many facts in the
objective world from which the idea is born
o Ex.: Democracy
Many thing in the objective world represent this • People, events, constitutions, legislative acts,
past and present institutions
o An idea is only as good as the degree that it is distanced from its source
No idea can sever its ties no matter how complex
o Bad ideas are a product of the rejection of objective facts
6. Match Words to Ideas
o If ideas are sound to the extent they faithfully represent the thing they will be clearly
communicable
But only if we clothe them in words that accurately signify them
o To ensure the word is proper to the idea
You must go back to the source of the idea
• The objective facts that are the foundation 7. Effective Communication
Be explicit
Especially important the more complex something is • When in doubt, spell it out
o Speak in complete sentences
Declarative statements require the same care as any statement
o Don’t treat evaluative statements as if they were statements of objective fact
Evaluative statements do not lend themselves to a simple true/false response Don’t invite unwarranted responses to statements
• This is what happens when an evaluative statement is passed off as a statement of objective fact
o If you want an evaluative statement to be accepted you must
argue for it
• True statements of objective fact are not open to argument
o Avoid double negatives
o Gear your language to your audience
Know your audience and speak in terms they can understand 8. Avoid Vague and Ambiguous Language
o A word is vague if its referent is blurred
You don’t know precisely what the word is pointing to The more general something is the more vague it is
Complex ideas are vague because they are rich in meaning and can mean different things to different people
• You must explicitly use them in a way that is clear to your meaning • Ex.: love, equality, democracy
o A word is ambiguous if it has more than 1 meaning and context does not clearly indicate
which meaning is intended
The only way to avoid ambiguity is to be explicit • Ex.: “Bear to the right”
o Rather, “Keep to the right” or “Grizzly bears to the right”
9. Avoid Evasive Language
o Always be straightforward in language
This ensures any reasonably attentive audience to not miss your meaning
o Evasive language can
Deceive your audience
Distort the sense of reality of the people who use it 10. Truth
o The whole purpose of reasoning and logic is to arrive at the truth of things o Truth has 2 basic forms
Ontological
• The truth of being or existence
Logical
• Truth as it manifests itself in thinking and language
o A statement is true if what it says reflects what is the case
A statement declares a correspondence of ideas in the mind (subjective facts) with real states in the world (objective facts)
• This is done through the medium of language
It is a matter of bringing harmonious juxtaposition to the subjective and the objective
• Focus on the objective order
o What determines truth or falsity is what exists in the real world
Thus logical truth is founded upon ontological truth
o Correspondence theory of truth
Understanding of the nature of truth
A correspondence between theory and objective reality
o Coherence theory of truth
Maintains that any given statement is true if it harmoniously fits into an already established theory or system of thought
Subordinate to correspondence theory This can be abused
• If a statement is judged to be true merely by virtue of the fact that it fits into an established theory or system of thought that itself does not correspond with or does so questionably
Part 2—The Basic Principles of Logic
The foundational truths that govern logical thinking 1. First Principles
o The principle of identity
A thing is what it is
• The whole of existing reality is not a homogenous mass
o It is a composition of individuals
The individuals are distinguishable from one another • Obviously it is not something other than what it is
o The principle of the excluded middle
Between being and nonbeing there is no middle state • Something exists or it does not exist
• The state of becoming is not between being and nonbeing
o There is no such thing as just becoming
There are only thing that become
o The state of becoming is already within the realm of existence
o The principle of sufficient reason
Also called the principle of causality There is a sufficient reason for everything
• Everything that actually exists in the physical universe has an explanation for its existence
• Nothing in the physical universe is self-explanatory or the cause of itself • If something is the cause of another thing
o It explains the very existence of that thing
o It explains why the thing exists in this or that particular way
The mode of its existence
o The principle of contradiction
It is impossible for something both to be and not be at the same time and in the same respect
• In the same respect refers to the mode of existence in question
o Ex.: you can be physically in New York, but mentally in Seattle o First principles are self-evident
They cannot be proven
• They are not conclusions that follow from premises • They are not truths dependent upon antecedent truths • They represent truths that are absolutely fundamental 2. Real Gray Areas, Manufactured Gray Areas
o A gray area is a situation in which the truth can’t be clearly established o Just because there is a situation in which you see no clear alternatives
Doesn’t mean there are no clear alternatives • You just don’t see them
o A negative can only be recognized as a negative because you already see the positive
3. There’s an Explanation for Everything, Eventually
o To solve a problem focus on the cause (of problem), not the effect (problem)
4. Don’t stop short in the search for causes
o Causes often arrange themselves in a series o If A->B->C
A is the cause of C as well as B 5. Distinguish among causes
o 4 types of causes
Efficient cause
• An agent whose activity brings something into existence
o Modifies its existence in one way or another
• Principle cause
o The ultimate explanation for something’s existence
• Instrumental cause
o passive
Final cause
• As applied to activity
o The purpose of activity
• As applied to an object
o The use to which the object can be put
Material cause
• The material out of which an object is composed
Formal cause
• The identifying nature of a thing
o That which makes it precisely what it is o Not every type of cause can be applied to everything
6. Define your terms
o The most effective way to avoid vagueness or ambiguity in logical discourse o Really defining the objects to which the terms apply
First we apply a word
• Second we further define what that word means 7. The categorical statement
o The most effective argument is one whose conclusion is a categorical statement
Tells us something that something definitely is the case • Certainty, without doubt, that something is • NO may, could be, might, etc.
8. Generalizing
o A general statement is one whose subject is very large in scope
Not necessarily inaccurate
o What makes a general statement sound is the fact that what is being attributed to the
class represented by the subject is:
True
Applies to the entire class
o Explicit language in general statements is important
Guards against any possible confusion on the part of an audience Leave out linguistic qualifiers like all, some, etc
• Implies that what is being said applies to the entire class
o 2 types
Universal statement
• Affirmative or Positive • Every or all or no statement
• Affirms or denies something about an entire class Particular statement
Part 3—Argument: The language of logic
Focus on argument; the public expression of logical thinking 1. Founding the argument
a. Every argument is composed of two basic elements i. Premise statement
1. Supporting statement
2. Starting point of an argument
3. Contains the known truth from which the inferential move begins 4. You can have multiple premises
5. Common logical indicators
a. Because, since, on account of ii. Conclusion statement
1. Supported statement
2. Accepted as true on the basis of the premise 3. Avoid multiple conclusions
4. Common logical indicators a. Therefore, thus, so 2. The move from universal to particular
a. Ensures a necessarily true conclusion
b. If it is true, a particular statement with the same subject and predicate is also true i. If you know something to be true about an entire group
1. Then it must also be true about any portion of the group 3. The move from particular to universal
a. Does not ensure a necessarily true conclusion
b. Knowledge of a part does not allow one to say anything definitive about the whole i. In some instances any attempt to make that move would yield a false conclusion ii. A whole can contain a part but not vice versa
iii. Ex.: stereotypes 4. Predication
a. The idea-connecting process by which we attribute something to something else b. Test of sound predication is that the ideas brought together belong together 5. Negative statements
a. Disconnect ideas
b. All things being equal if the same idea can be communicated both affirmatively and negatively it is better to opt for the affirmative
i. Focus on what is the case rather than what is not
c. Negative statements can be effectively used as corrective responses to false statements
6. Making comparisons
a. A statement is the linguistic expression of the most fundamental comparison the mind makes when it relates one idea (the subject) to another (the predicate)
b. A judgment is the mental act by which we link ideas in a way that enables us to make coherent statements about the world in which we live
i. Sound to the extent that the relationship forged between 2 ideas is real and objective
c. It is not the quantity of similarities/differences but the significance of them i. No quantity of qualities will matter if a single significant one is left out d. No 2 things can be so completely alike that they cease to be 2 things
7. Comparison and argument
a. When argument bears on comparison the purpose is to demonstrate (prove by argument) that the two things are similar
b. Ensure all characteristics are significant and none are left out c. Argument by analogy
i. Relation of similarity between two things
ii. Of two things I am comparing, one of them, A, is better known to you than B
8. Sound argument
a. For an argument to be sound it must be so with respect to its contents and its structure i. An argument is sound to its contents if all statements it is composed of are true ii. An argument has valid structure when true premises ensure a true conclusion b. Conjunctive argument
i. Expressed A and (.) B
ii. A and B represent complete statements 1. Says both A and B are true 2. A therefore B
c. Disjunctive argument i. A v (or) B
1. Either A or B
a. Not both and not none 9. Conditional argument
a. Hypothetical argument i. If/then
b. A certain condition is set with the idea in mind that if that condition is met then certain consequences will follow
i. The 1st
statement is the antecedent; the 2nd
is the consequent
ii. The stronger the condition between the antecedent and the consequent, the more probably that the consequent will turn out to be true
c. A -> B
i. If A comes about then B must come about ii. – B therefore -A
10. Syllogistic argument
a. Reflects the way the human mind habitually operates
i. Connects ideas in such a way that conclusions can be drawn from connections b. Every M is P; Every S is M; Therefore every S is P
i. M is the middle term; P is the major term; S is the minor term 11. The truth of premises
a. If we start with a false premise, a valid (structurally sound) argument will only lead to a false conclusion
12. The relevancy of premises
a. Weak premises, even if true, will not support and argument i. Premise should point the way to the conclusion 13. Statements of fact, statements of value
a. the test for the soundness of a statement of value is the extent to which it is founded upon objective fact
i. the broader and more solid the foundation, the more reliable the statement 14. Argumentative form
a. It is possible to have an argument with true premises but a false conclusion i. This is due to a defective form
b. The middle term must be universal at least once to enable it to make the connection that must be made between minor term and major term
i. This will yield a conclusion that is not simply true but necessarily true c. Chipmunks are mammals; squirrels are mammals; therefore chipmunks are squirrels
i. Invalid because it attempts to identify the 2 subgroups because they are in the same larger group
15. Conclusions must reflect quantity of premises
a. The quantity of a statement is established by the quantity of the subject term i. If the premises begin with some the conclusion must begin with some 16. Conclusions must reflect quality of premises
a. If a statement that serves the conclusion of an argument is negative, at least one of the premises in the argument must be negative
17. Inductive argument
a. a deductive argument starts at the general and moves to the particular i. productive of necessary conclusions
ii. single starting point, the major premise 1. established fact
2. starting from a statement that is known to be true we can draw out of it and make explicit what is implied in the initial statement
b. An inductive argument starts from the particular and moves to the general i. Has the capacity to produce probable conclusions only
ii. Ordered to make reliable generalizations about large groups of things 1. hypothesis
18. Assessing argument
a. The first thing to ascertain is whether there is an argument i. Are the two basic elements present
b. Are the premises true?
d. Is the argument structurally sound
e. The force of an argument depends on the extent to which it reflects the objective order of things
19. Constructing an argument
a. Be mindful of the two basic elements b. Focus attention on the premises
i. Truth
1. A statement may be true but not expressed in a way where the truth is readily evident
ii. Strength
1. Relevance
a. To conclusion b. To audience Part 4—The sources of illogical thinking
Attitudes and frames of mind that promote illogical thinking 1. Skepticism
a. Should be selectively employed
i. A distinction should be made between skepticism as 1. Permanent attitude
a. Should be avoided
b. Subverts the reasoning process before it begins 2. Fitting response to a particular situation
b. Extreme skeptic
i. There is no truth c. Moderate skeptic
i. Truth exists but the human mind is incapable of attaining it 2. Evasive agnosticism
a. An agnostic maintains that they lack enough knowledge regarding a particular issue to be able to make a definite judgment about it
i. Neither denies the existence of truth or its attainability 1. Simply claims ignorance
b. Evasive agnosticism is the attitude that attempts to pass off vincible ignorance as invincible
i. Result of indifference or laziness 3. Cynicism and naïve optimism
a. Illogical positions based on prejudice
i. A cynic is someone who makes emphatically negative estimates without sufficient evidence
ii. A naïve optimist is someone who makes emphatically positive estimates without sufficient evidence
1. Blind to the pitfalls
4. Narrow-mindedness
a. Limited scope of vision
b. Refuses to consider certain alternatives only because they do not meet his prejudiced assumptions about what is and is not worth pursuing
c. to be tolerant of everything is to value nothing
i. the search for truth necessitates imposing judicious limitations on the investigative area
5. Emotion and argument
a. Keep emotion out of an argument
i. The more intense an emotional state, the more difficult it is to think clearly ii. A conclusion should be accepted not because it feels/sounds good, but because
it is seen as true and is worthy of acceptance b. Manipulate people by appealing to emotions
6. The reason for reasoning
a. Reason can be employed for both good and bad 7. Argumentation is not quarreling
a. Argument is rational discourse
i. The object is to get at the truth
ii. The object of quarrelling is to get at other people
b. Do not waste time trying to argue with people who won’t or can’t 8. The limits of sincerity
a. Sincerity is a necessary condition for sound reasoning but not sufficient
i. If you do not have regard for the position that you advocate you abuse reason
9. Common sense
a. It is common sense in that it is shared by those animals considered rational Part 5—The principal forms of illogical thinking
• Fallacies—the particulars of illogical thinking
o Formal
Those that deal with form/structure of an argument
o Informal
Logical mistakes 1. Denying the antecedent
a. A->B; -A; Therefore –B
i. Ex.: if joe is running, then he is moving; Joe isn’t running; Joe isn’t moving b. If A comes about then B will come about
i. This doesn’t mean that the absence of B means the absence of A 1. A is just the a condition for B
2. Affirming the consequent a. A->B; B; Therfore, A
i. Ex.: If Joe is running, then he is moving; Joe is moving; therefore he is running b. A is a condition for B, but A may not be the only condition for B
3. The undistributed middle term
a. The middle term (the term appearing in the premise but not in the conclusion) must be a universal term (distributed) at least once in order for it to have the proper scope to make the connection between major and minor
i. Failing to happen is the undistributed middle term 1. Guilt by association
ii. Ex.: several Nazis were members of the Kaiser club; Hans was a member of the Kaiser Club; Therefore, Hans was a nazi
1. It may lay suspicion on Hans, but it doesn’t allow proclamation that he is definitely a nazi
4. Equivocation
a. An equivocal term has more than a single meaning i. Ambiguous
1. Deliberate ambiguity is a fallacy
b. On the surface the argument appears to have 3 terms but because a term is ambiguous the expression essentially has 4
i. M—P; S—M; /S—P
1. M—P; S—Q;/S—P
ii. Ex.: Loving one’s neighbor is a mark of altruism; Don Juan was a great lover; It follows that he was an altruist
1. If the premises were stated in terms they actually mean then it would show that no conclusion is possible
a. Love of neighbor is a mark of altruism; Don Juan was a philanderer
i. There is now nowhere to go within the argument 5. Begging the question
a. Attempts to get around the whole argumentative process i. Appears to be an argument but is not
ii. Lacks real premises
iii. Statements will differ verbally, but not in terms of their content
b. Ex.: all the people at the table had their heads shaved; Jim was at the table; therefore, Jim had his head shaved
i. The first statement appears as a major premise
1. However the only way to make it is to have prior knowledge of the situation
a. So it is merely a restatement of the conclusion c. Arguing in a circle / vicious circle
i. 1st
1. The process is then reversed; B now supports A as A becomes the conclusion
2. Can be seen as two separate arguments 6. False assumptions
a. To assume something is true is to take it to be true w/o being positively certain it is i. Sometimes this helps get the reasoning process off the ground
b. A false assumption is such because it can independently be demonstrated false c. If you assume that your audience has a certain knowledge that it doesn’t
i. Then it won’t follow your argument 7. The straw-man fallacy
a. Deliberately distorting an argument so as to weaken it 8. Using and abusing tradition
a. Tradition is an elaborate set of precedents
i. The fact that things have always been done a certain way does not justify keeping them so
1. Habit is a powerful influence b. Keep focus on the practice not the history
i. Longevity is not reason enough to dis/continue doing something 9. Two wrongs don’t make a right
a. “It is all right to do _______ because _______ has already been done”
b. Rests on the assumption that precedent alone provides emphatically insufficient justification for an action
10. The democratic fallacy
a. The assumption that the mere fact that most people believe proposition X to be true is sufficient evidence to allow us to conclude that proposition X is true
i. Though it is not easy to stand up to the crowd 1. Something is still on objective fact 11. The ad hominem fallacy
a. When a person responsible for the argument is deliberately attack and the argument itself is ignored
i. In argumentation we respond to the argument not the person behind it b. Intention is to divert an audience’s attention from the argument
12. Substituting for the force of reason
a. Using coercion or raw power instead of the use of force of reason 13. The uses and abuses of expertise
a. Being satisfied with the argument simply because of the expertise of the person back it b. It is perfectly legitimate to appeal to the views of if they are relevant to the point
i. Strongest expert evidence incorporates reasons the experts advance for holding a certain position
14. The quantifying of quality
a. Expressing quality in quantitative terms i. No quality can be quantified
1. If quality could be perfectly translated into quantity there would be no basis for the distinction between the two in the first place
15. Consider more than the source
a. Assuming something isn’t simply because of the source that provided it
i. It is relevant to consider the source of something whose qualities we are assessing
1. But we must go beyond that 16. Stopping short of analysis
a. Analysis is only productive if it is complemented by synthesis
b. Analysis is not simply to know the individual parts that make up a thing i. But to know how they relate to one another
17. Reductionism
a. When we selectively focus on only some of the parts of a composed whole i. Ex.: calling attention exclusively to negative traits
1. In doing so trying to pass it off as bringing attention to the whole 18. Misclassification
a. Misclassifying things because we fail to properly identify them in the 1st
place i. Doing so because of not paying attention
19. The red herring
a. Introducing emotionally volatile info, deliberately calculated to agitate a specific audience
i. This is an direct appeal to emotion, not reason
ii. The info introduced has nothing to do with the issues in the argument 20. Laughter as diversionary tactic
a. Trying to dodge the inability to come up with a reasoned response to an argument by pretending that it is not worth taking seriously
i. Powerful way of dismissing an argument 21. Tears as diversionary tactic
a. Deliberately obscuring issues through the cynical manipulation of emotion
b. Intentionally ignoring or downplaying the pertinent issues instead focusing on matters that are either peripheral or irrelevant
i. In turn appealing directly to the emotions of the audience to gain sympathy 22. An inability to disprove does not prove
a. One can’t claim to be right simply because no one can prove them wrong
i. The fact that there is no concrete proof against a position does not constitute an argument in favor of it
23. The false dilemma
a. When a situation entailing several possibilities is attempted to be persuaded down to only two
i. A distortion of the actual state of affairs b. Creates a false sense of urgency in an audience
ii. “A, admittedly, is not all that pleasant a choice, but the only alternative you have is B, and that is awful. Certainly you would not want that!”
24. Post Hoc Ergo Propter Hoc
a. “After that, therefore on account of that”
b. 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 c. The temporal precedence of one event over another is not irrelevant in considering
whether there might be a causal relationship i. But the information is not conclusive 25. Special pleading
a. When we selectively omit significant information because it would weigh against a position we are promoting
26. The fallacy of expediency
a. When we ignore every aspect of a means other than its capacity to achieve a desired end
i. Not enough to point to the bottom line as if it were all that mattered
b. A willingness to adopt any tactic for the sole purpose of bringing about a desired end 27. Avoiding conclusions
a. Adopting the principle that problems are insoluble and conclusions unreachable 28. Simplistic reasoning
