Logical Reasoning
Flawed Reasoning: 16) Circular Reasoning
Assumes something to be true as support for proving it true EXAMPLE -"all farmers are poor because if you are a farmer, you do not have much money" DESCRIBED ON LSAT -" takes for granted the very claim that it sets out to establish" -"it assumes what it seeks to establish" -"presupposes the truth of what it sets out to prove" -"the support offered for the conclusion is a mere restatement of the conclusion"
Flawed Reasoning: 12) Appeal Fallacies - Appeal to Popular Opinion, Common Practice, or Numbers
Bases a conclusion on popular opinion, or states that a claim is true merely because the majority believes it to be true. -Usually occurs in advertisement on the LSAT - "advertisement says this..." RED FLAG DESCRIBED ON LSAT -" The argument appeals to popular opinion rather than providing a logical basis for the conclusion." -"Relies upon common practice to determine the acceptable practice." -"Treats popular opinion as conclusive evidence regarding a claim."
Flawed Reasoning: 17) Ambiguous Use of Key Terms
Changing the usage or meaning of a key term during the course of the argument EXAMPLE -"many people supported the new building in town, however, when the building collapsed from an earthquake, the city architect blamed it on the lack of support" DESCRIBED ON LSAT -"IT confuses 2 different meanings of the word "support" -"allows a key term to shift in meaning from one use to the next" -"fails to define the term"
Flawed Reasoning: 2) Conditional Statements (formal logic or conditional reasoning) The Error and Flaws that will occur 2: Confusing a sufficient condition for a Necessary Condition
Examples: 1) confuses a SC with a required condition 2) treats the nonexistence of something as evidence that a required precondition for that thing also did not exist 3) mistakes being sufficient to justify a failing grade with being required to justify a failing grade. - "if you miss the final exam, you will receive a failing grade for the course" -shortened: "if M then F" - described on LSAT: " treats the nonexistence of something as evidence that a required precondition for that thing also did not exist. "
True or False: Premises are NOT always true.
FALSE. Premises are always true. they are fact. Even if they seem unlikely to be true or you know it to be false, accept it as a fact.
Weaken the Conclusion Questions: True or false- Strongly worded answers tend to be the correct answers?
False. Strongly worded answers tend to be INCORRECT because they are too extreme to achieve the goal required by the question. However, strongly worded questions can have a very strong weakening effect on the conclusion.
Identify the Conclusion Questions: They ask you to do what?
Identify the conclusion or main point of the argument.
Flawed Reasoning: 13) Straw Man
Misrepresentation of an opponent's position - presents a weaker version (straw man) of the opponent's argument and attacks that weakened argument rather than the original argument. EXAMPLE - your opponent's argument is " a strong knight in shining armor" and you are supposed to fight that knight. - Straw Man- Put the Knight in fake armor - you attack the knight in fake armor, you win, and say you defeated the actual Knight (the original argument) - this often involves rephrasing the opposing argument in order to make it vulnerable to attack. EXAMPLE - Person A: "we should liberalize the laws on beer - Person B: "No, any society with unrestricted access to intoxicants loses its work ethic and goes only for immediate gratification." DESCRIBED ON LSAT -"portrays opponent's views as more extreme than they actually are" -"rephrases the opposing viewpoint in order to make it more vulnerable to criticism" -"distorts the proposal made by the advocates" -"mistakes the original position held by the politician in order to make it easier to refute"
Weaken the Conclusion Questions: Strongly worded words include
Never none no one will ever every in all cases always all every time exclusively
Assessing Strength Sample Argument: Is this argument strong? Fido is a dog. All dogs have 4 legs. Therefore, Fido can run fast.
No. Although the premises are true, they DO NOT support the conclusion. this argument Assumes that 4 legs=fast and that is too big of an assumption to make.
Truth and Validity: Are the premises true?
On the LSAT, all premises are 100% true.
When looking at a stimulus, you should not bring any _ _ when considering answers.
Outside knowledge. The passage gives you everything you need to know about how to answer the question.
What is the conclusion supported by?
Premises
Flawed Reasoning: 12) Appeal Fallacies - Appeal to Authority
Relies on the opinion or statements of Authority in order to justify the conclusion. This looks like: - Source A says that Source B... - Source A is an authority - therefore, B is true - "the bishop has declared that chocolate is the food of the devil, therefore chocolate is evil." DESCRIBED ON LSAT -"the argument relies upon an expert opinion in a matter to which their expertise is irrelevant." -"accepts a proposition on mere authority, without requiring sufficient justification."
First part of a question
Stimulus
Flawed Reasoning: True or False- Answer Choices have common flaws on the LSAT?
TRUE. A few flaws appear frequently on the LSAT. -Both as correct and incorrect answers on the exam
True or False: Conclusions should be critiqued and questioned and supported by your premises.
TRUE. Conclusions should always be critiqued and questioned. Looking at a conclusion critically to ask yourself if it's true if it's supported by the evidence by your premises.
Flawed Reasoning: True or False- Flawed reasoning questions are similar to method of reasoning questions?
TRUE. both questions ask you to ONLY identify the structure of the method or the flawed portion of the argument.
Identify the Conclusion Questions: Once you pick out the stimulus and conclusion, how do you know what the right answer is?
The correct answer will be a paraphrased version or rewording of the conclusion.
Conclusion identifying words:
Therefore, hence, should, concludes, as a result, thus, clearly, proves that, shows that, so, accordingly, for these reasons, follows that, must be.
Parallel Reasoning: Paralleled Elements
These MUST be paralleled from your stimulus to your answer 1) the METHOD or STRUCTURE of the argument - look for common structures - conditional reasoning, cause and effect, analogies, comparisons, etc. 2) the CONCLUSION of the argument - includes: however, actually, but, surprisingly - the certainty levels of the conclusions must match - always = always, every time, all, for sure, 100% - PROBABLY = most likely, often, likely, most, majority - "no one is taller than Sam" also means "everyone is shorter than Sam" 3) the PREMISES of the argument - diagram by listing each premise and matching it to your argument 4) the VALIDITY of the argument - valid arguments: must parallel a valid argument - invalid arguments: identified as flawed reasoning in the question stem
Weaken the Conclusion Questions: Ask you to do what?
To find the answer choice that has the most negative effect on your conclusion/weakens it.
True or False: There can be more than one right answer choice?
True. There can be more than one eligible answer, but you must pick the BEST answer out of the two.
Identify the Conclusion Questions, True or False: There can be more than one concluding statement?
True. but you must identify the main conclusion/main point.
Principle Questions: An alternate approach
Type 1: Must Be True Questions - ex: stimulus - all people are mortal - answer - Bob is a person, therefore bob is mortal. Type 2: Justify the Conclusion - a scenario with a conclusion in the stimulus and we are looking for a general principle that matches with our scenario - that principle will make our argument CONCLUSIVE -ex: "Bob is a person, therefore Bob is mortal" - answer - "all people are mortal" Type 3: Parallel Reasoning - specifics in both our stimulus and answer - we are looking to match up the underlying principle/structure - ex: "All people are mortal, Bob is a person, therefore, Bob is mortal" - Ans: "All spies carry guns. Max is a spy; therefore, he carries a gun.
Flawed Reasoning: 12) Appeal Fallacies - Appeal to Emotions
Uses emotional situations or language to try to force an issue or persuade the reader DESCRIBED ON LSAT -"an attempt to persuade the reader thru an emotional appeal" -"the speaker appeals to emotion rather than to reason or logic." -"employs emotive language in supporting the conclusion"
Flawed Reasoning: 4) Survey Errors
a) a sample is too small to be relevant -asking only 5 people who they will vote for and using their response to predict the next president b) using a biased sample -asking only owners of Nissans who they will vote for c) Inaccurate responses -asking respondents whether they have cheated on their spouse -a question they will likely lie about d) using a poorly designed or biased question survey -"would you prefer that we send more troops to the war or keep existing numbers there?" -this question doesn't allow for the possibility of withdrawal -ASK YOURSELF: "does this survey achieve the results necessary to support the conclusion?"
Most stimuli are...
arguments
Stimuli arguments are made up of a..
conclusion
Flawed Reasoning: 2) Conditional Statements (formal logic or conditional reasoning) The Error and Flaws that will occur 1: Confusing a necessary condition for a sufficient condition
examples: 1) confuses a required condition with a sufficient condition 2) treats something that is necessary to bring about a state of affairs as something that is sufficient to bring about a state of affairs 3) based upon an assertion that something is necessary to achieve the desired result, the argument concludes that that thing is sufficient to achieve the desired result. - "if you miss the final exam, you will receive a failing grade for the course" - shortened: "if miss then fail" or "if M then F" - if you are asked to find something that confuses a NC for a SC, it would be described as: - "mistakes being sufficient to justify a failing grade with being required to justify a failing grade." - shortened- "it would confuse our NC (F) for a SC" so our NC is failing and being confused for a SC could tell us that we missed the exam, but it's not Sufficient to know we missed our exam.
Method of Reasoning Questions: These ask you to do what?
identify the method of reasoning used in the argument. This means analyzing your argument and determining a general way of describing the means or method of arguing, NOT the argument itself.
Premise identifying words:
since, because, after all, as seen from, for example, given that, indicated by, as shown by, as a result of, demonstrated by, due to, based on the fact that.
Truth and Validity: What is Validity?
the logical structure of our argument and how the premises provide support to that conclusion.
What is a premise?
the reasons and the support for leading to the conclusion.
Parallel Reasoning: Un-paralleled Elements
these two DO NOT have to be paralleled 1) the ORDER in which the argument is presented 2) the TOPIC - almost always will be a different topic
Strengthen the Conclusion Questions: Ask you to do what?
to find the answer choice with the most POSITIVE effect on the conclusion.
Flawed Reasoning: 10) False Analogies Type 2
"When 2 concepts, objects, or events are compared, but they are too dissimilar to make an effective analogy." Example - "the best way to win a race is to train hard for months leading up to the race and then take a break from all running for at least 5 days prior to the race. Similarly, the best way to close a business deal is to work hard on it for months, and then take a break at least 5 days prior to completing the deal."
Sample Argument: What is the premise and the conclusion? "Because he ate too much, he became sick."
* Because- premise identifying word * "he ate too much"- supports the conclusion * Eating too much is the reason for our conclusion (becoming sick) * Conclusion- becoming sick.
What is a counterargument/counter-premise?
*Extra information that goes against the main conclusion *They do not support the conclusion
Flawed Reasoning: How to answer these questions Part 1: Ask yourself as you look at your answer choices
- "does this occur?" - "does it happen in my stimulus?" - if the answer choice does NOT happen in my stimulus, then it is the WRONG answer - if the answer choice DOES happen in my stimulus, then you move on to step 2.
Principle Questions: Type 2
- A specific scenario in the stimulus and a general principle in the answer choice 1) stimulus = specific scenario (Lisa is mortal) 2) answer = General Principle (all people are mortal)
Parallel Reasoning: Flawed Questions
- Ask you to match up the argument in stimulus with that in your answer choices, but there's a flaw in your argument. - Focus on that flaw as it is part of the structure QUESTION STEMS 1) "The questionable reasoning in the argument above is most closely paralleled by which one of the following?" 2) "The flawed reasoning in which one of the following is most similar to the flawed reasoning in the argument above?"
Principle Questions: Type 1
- Has a general Principle right in the stimulus and specifics in the answer choice - Stimulus = General Principle (ex- all people are mortal) - Answer = Specific Scenario (ex- Lisa is mortal)
Flawed Reasoning: 11) False Dilemmas (false dichotomy/fallacy)
- Involves a situation in which only 2 alternatives are considered when in fact, there are other options. - Makes the assumption that only 2 options are valid. EXAMPLE - "you are either with us or against us." - "only artists with great success make enough money, therefore, government programs must be offered to maintain a society with plenty of artists." DESCRIBED ON LSAT -" falsely assumes that only 2 options are available to participants." BE CAREFUL -not to confuse False Dilemmas with a situation where only 2 options do exist. 1) established by author in argument "only option A or B are possible." 2) Factually correct "dead or alive"
Principle Questions
- Match up the principle in your stimulus to the principle in your correct answer - Principles can be: 1) General - " a good cook has good techniques and improvises" 2) Specific - "Henry is a good cook because he has technique and improvises"
Principle Questions: Type 3
- Specific scenarios in both the stimulus and the answer choice 1) stimulus = specific scenario (Lisa is mortal) 2) answer = specific scenario (Lisa is mortal)
Flawed Reasoning: Asks you to identify what?
- a flaw or error in reasoning i your stimulus
Parallel Reasoning
- asked to match up the structure of the argument in the stimulus with the structure of the argument in an answer -the topic of arguments will be different -you are looking for argument that shares the same structure - Pay attention to words like "all" "some" "none" etc. because they play a part in the structure and answers DIAGRAMMING -try quick diagrams: shorthand notations of the argument structures -note each element: "all entities in Group A have trait C" -then check each answer choice to see if it has each element EXAMPLE QUESTIONS ON THE LSAT -"which of the following most closely parallels the reasoning in the argument above? 2) "which one of the following arguments is most similar in its pattern of reasoning to the argument above?" 3) "the structure of the reasoning in the argument above is most parallel to that in which of the following?" 4) "which one of the following arguments is most similar in its logical methods to the argument above?" TIME CONSUMING -Consider skipping and coming back when you have time later
Flawed Reasoning: 1) Attack on the Speaker
- attacks the person making the argument instead of the argument itself. - often occurs when the stimulus includes a criticism of another argument, and the criticism focuses on the source or proponent of the argument as opposed to the argument itself. - These generally attack: 1) the proponent's actions or 2) the proponent's motivations.
Flawed Reasoning: How to answer these questions Part 2: ask yourself, now that we know this answer choice occurs, "does it affect our argument in a negative way?" "Does it destroy the argument or substantially weaken it?" "Is it a problem?"
- if it IS a problem, you found your correct answer. - if it is NOT a problem, you can cross it out.
Flawed Reasoning: 2) Conditional Statements (formal logic or conditional reasoning) Sufficient Conditions
- if suff condition occurs, then the necessary condition definitely occurs. - if they do not occur, then we know nothing more. - if it occurs, it is sufficient information to tell us that the other (necessary) condition occurred. - If A then B. A is our sufficient condition and B is our necessary condition.
Flawed Reasoning: 2) Conditional Statements (formal logic or conditional reasoning)
- involves the sufficient condition with the necessary condition
Flawed Reasoning: 2) Conditional Statements (formal logic or conditional reasoning) Necessary Conditions
- they do not occur then the sufficient condition does not occur - if they do occur, we know nothing more - it is necessary for the necessary condition to occur in order for the sufficient condition to occur, so if the necessary condition does not occur then the sufficient condition cannot occur.
Flawed Reasoning: Paraphrasing Answers
- try and describe the flaw used in the argument - use general/abstract terms and descriptions (not specifics) - Example- "since my cat loves to eat chicken, all cats love to eat chicken." - abstract flaw: concludes that all members of a group have a trait on the basis that one of them has the trait. - specific flaw: just because my cat loves chicken doesn't mean all cats will.
Flawed Reasoning: 5) Generalizing
- using a few specific cases to make an overly broad generalization -similar to a survey error where it's too small of a sample size -generalization occurs when a small number of instances is used to make a conclusion about a greater group -ex) asking your parents who they are voting for, and they both say Candidate A, therefore, you say Candidate A will win.
Principle Question: Questions that do NOT match the principle
- you may be asked to find the answer that does not match the principle QUESTION STEM - "Each of the following principles is consistent with the argument EXCEPT?" ANSWER CHOICES - each answer choice will match the stimulus except for one -that one that does not match WILL be your answer
Flawed Reasoning: 10) False Analogies Described on the LSAT
-"Treats as similar, 2 cases that are different in critical aspects" -"mistakenly assumes that 2 scenarios that are different with respect to important traits do not in fact differ." REMEMBER -analogies compare things so it will always be 2 different things, but make sure they are not TOO dissimilar. - apples to oranges could be VALID or INVALID - valid - because they are fruits, their seeds must regrow new fruit - invalid - because they are fruits, they must be the same color.
Method of Reasoning Questions: Common elements used for reasoning
-analogies -agreement or disagreement by the author -attacking another argument -counter examples to refute an argument -additional evidence to support or refute a claim -weaken a claim by identifying a logical error in the argument
Flawed Reasoning: 6) Groups - Composition Errors
-assigning a characteristic of part of the group to the whole group example -"my sister and her teammate have red hair, therefore, everyone on their team must have red hair." -"Jared loves hockey and baseball so he must love all sports" HOW THIS IS DESCRIBED ON THE LSAT -"takes a characteristic held by one member of a group and infers that it is shared by all members of that group" -"assumes that the view of a few persons represents the views of all similar persons"
Flawed Reasoning: 6) Groups - Division Errors
-assigning a characteristic of the group to a member of the group example -"the union decided not to accept management offers and the negotiations have come to a standstill. Mariam is a member of the union and so she must have voted against managements offers. " HOW THIS IS DESCRIBED ON THE LSAT -"presumes without providing justification that what is true of a whole group must also be true of its constituent parts."
Flawed Reasoning: 8) Constant Assumptions
-assuming that factors will remain constant over time -So, factors that held in the past may not hold in the future/present EXAMPLE -"in 1988, there were far more male law students than females, so the same must hold today." - many schools today have more female law students than men -"all of my past sales meetings have met with success, so this one will be successful" -this one could go bad DESCRIBED ON LSAT -"assumes without justification that what was held true in the past will hold true in the future." -"considers evidence about a present situation as evidence for the continued occurrence of that situation."
Partial Method of Reasoning Questions: ask you to do what?
-identify a method or structure of reasoning used in only a small part of your argument - this is opposed to looking for the argument as a whole
Flawed Reasoning: 12) Appeal Fallacies
-objective argument that stands on its own legs, makes some form of appeal, pleading with the listeners to accept a point without further questioning. -makes appeal pleading to emotion or some other source. APPEALS TO... 1) Authority - "scientist said so..." 2) Emotions - (please or I will cry) 3) Popular Opinion - "everyone is doing it" - there is also appeal to fear or force (gaining compliance thru threat), appeal to common belief (others believe it to be true, so it must be true), appeal to novelty (newer is better), Appeal to pity/sympathy, Appeal for ridicule (mocking the other person's claim), and appeal to tradition (it has always been done this way, so this way is right).
Flawed Reasoning: Common Flaws (18)
1) "appealing to illegitimate authority" - appears often as the correct answer or incorrect answer 2) attacking the speaker as opposed to the argument itself 3) formal logic or conditional reasoning errors 4) confusing cause with effect (or vice versa) 5) Survey Errors 6) Using a few specific cases to make an over broad generalization. 7) Errors regarding groups and parts of such groups 8) numbers and % errors 9) assuming that factors remain constant over time 10) misuse of evidence 11) poor or dissimilar analogies 12) False Dilemmas 13) Appeal Fallacies (appealing to emotion, the masses, authority) 14) Straw Man 15) Irrelevant evidence/ Support 16) Self contradictions or incompatible statements 17) Circular Reasoning 18) Ambiguous use of Key Terms
Flawed Reasoning: 4) Survey Errors presented on the LSAT
1) "generalizes from an unrepresentative sample" 2) "states a generalization based on a selection that is not representative of the group about which the generalization is supposed to hold true" 3) "uses a result from an insufficiently sized sample that may not properly represent the group as a whole"
Flawed Reasoning: 5) How Generalizing Can be Described on the LSAT
1) "generalizes from an unrepresentative sample" 2) "uses results from an insufficiently sized sample that may not properly represent the whole group as a whole." 3) "supports a universal claim on the basis of a single example." 4) "assumes a broad result based on the results of only one experimental case." 5) "makes an overly broad assumption based upon a small number of occurrences."
Flawed Reasoning: Attack on the Speaker examples of how this can be described on the LSAT:
1) "it focuses on the source of the argument as opposed to the argument itself." 2) "Assumes that the speakers motivations invalidate their argument" 3) "Confuses the proponent's actions with their proposed claim" 4) "criticizes the character of the opponent." 5) "reaches a conclusion about the value of a claim based on evidence about that claims source." 6) "assumes that the questionable character of a claims proponent invalidates the claim."
Identify the Conclusion Questions: 5 steps for identifying he conclusion or main argument
1) Classify each sentence or portion of a sentence as either a conclusion or premise 2) identify the answer that most closely states the conclusion or main point 3) Be sure to identify the main conclusion and NOT the sub-conclusion 4) Do not assume that the conclusion will come at the end of the argument 5) Use conclusion identifying words to help find the conclusion.
Flawed Reasoning: 15) Self Contradictions/Incompatible Statements
1) Contradictory Statements as support for the conclusion OR 2) statements that contradict the conclusion itself DESCRIBED ON LSAT -" Makes a conclusion based on contradicting premises" -" Incompatible assumptions are made" - "Assumes something that is later denied" - "evidence offered in support of the conclusion in fact contradicts the conclusion"
Strengthen the Conclusion Questions: 2 ways to strengthen the argument
1) Improve or support one of the premises 2) Add a new premise that supports or improves the conclusion.
Sample Argument: Truth and Validity. "All people have Brains. James is a person. Therefore, James has a brain."
1) This argument is both true and valid. 2) it is true that people have brains. 3) the logical structure is valid.
Flawed Reasoning: 9) Misuse of Evidence
1) Treating some evidence against a position as proving that position false. (Only a little evidence/not enough to prove) DONLSAT- "The critics error in assuming that providing evidence against an argument achieves the result of showing the conclusion of that argument to be false." 2) Treating some evidence for a position as proving that position true DONLSAT- "The critics mistakenly assume that providing some evidence to support their claims proves their claims." OR "the argument takes evidence demonstrating that its conclusion could be true as evidence sufficient to demonstrate that the conclusion is true." 3) treating a lack of evidence against a position as proving that position true. Just because you don't have evidence against a position, does not mean it's true) DONLSAT- "the author mistakenly assumes that a lack of evidence against the theory proves that theory to be true." OR "Taking a mere lack of evidence as sufficient support to prove a claim to be true." 4) Treating a lack of evidence for a position as proving that position false. We have a position, we show that there is no evidence for it, and then decide that it is false.) DONLSAT- "the author mistakenly assumes that a lack of evidence for the theory proves that theory to be false." OR "Taking a mere lack of evidence as sufficient support to prove a claim to be in fact false"
Critical Thinking: Think about whether the argument is strong or weak. What 3 questions should you ask yourself to determine whether the argument is strong or weak?
1) What assumptions are missing? 2) What assumptions would make my argument stronger? 3) What would make it conclusive?
Identify the Conclusion Questions: Common question types for identifying the conclusion (2)
1) Which one of the following statements most accurately expresses the main point of the argument? 2) Which one of the following most accurately expresses the conclusion of the argument?
Method of Reasoning Questions: how to eliminate wrong answer choices
1) cross off any that contain an element or structure clearly not used in the stimulus- if an answer mentions an analogy but there isn't an analogy in the stimulus, it is incorrect. 2) look for elements that are not included in the stimulus 3) right answer= all of its elements represented in the argument
Method of Reasoning Questions: Possible answers that describe a structure
1) determines that all entities have a particular trait because on entity has that trait 2) implies a characteristic of one creature upon all creatures of that type
Method of Reasoning Questions: the 3 ways to Approach the stimulus
1) identify the conclusion and premises 2) paraphrase the structure of the argument- focus on the basic elements included, so if there is an analogy in the argument, an analogy must be mentioned in your answer choice. 3) be precise about the language used- do not mistake a reference to some entities as a reference to all entities
Flawed Reasoning: 3) Confusing Cause with Effect (or vice versa)
1) mistaking an effect for a cause 2) mistaking correlation for a cause -2 events are correlated, but it doesn't necessarily mean that 1 causes the other. 3) assuming a casual relationship on the basis of a sequence of events - just because something came first, doesn't mean that that thing that comes after was caused by it. 4) failing to consider alternate causes for the effect or alternate causes for both the cause and effect.
How can you identify a premise?
1) premise identifying words 2) by looking for what is the support for the other part of your argument/conclusion.
A passage includes either a:
1) short argument 2) a set of facts
Method of Reasoning Questions: 4 ways to approach these questions
1) the answer choices do not use any of the same words or topics as the argument 2) the answer choices provide a general description of the technique 3) understand the structure or method used in the argument rather than the specifics used in it. 4) summarize the argument as you read it
Flawed Reasoning: Common Question Stems
1) the argument is most vulnerable to criticism on the grounds that it... 2) the argument is flawed in that it... 3) a questionable technique used in the council member's argument is that of... 4) the argument is flawed in that it presumes, without providing justification that...
Method of Reasoning Questions: 3 wrong answer choices
1) they add an extra element that is not included in the argument- could have the structure of the argument correct, but add an additional element to it 2) answers that go too far or do not copy the precise language of the argument- if the argument discusses some entities and the structure/answer choice goes too far by talking about all the entities, then it is incorrect. 3) answers that are exactly the opposite of the correct answer
Sample Argument: Truth and Validity. "All men are mortal. Socrates is mortal. Therefore, Socrates is a man."
1) this argument is true but not valid. 2) logical structure is broken even though our conclusion is true, the argument is broken. 3) Facts: men are mortal AND Socrates is Mortal. * However, this is not enough information to tell us that Socrates is a man.
How do you asses strength in an argument?
1) validity- if your argument is not valid, it is a very weak argument. 2) Do my premises properly support my conclusion?
Flawed Reasoning: 14) Lack of Evidence or Use of Irrelevant Evidence/Support
1) very little (if any) evidence to support the conclusion or 2) they provide evidence that is irrelevant to reaching the proposed conclusion DESCRIBED ON LSAT -" the evidence presented in support of the claim in fact provides no support for that claim" -"the author provides evidence which does not serve the purpose for which it is used" -" the argument fails to give any reason for the conclusion reached"
Weaken the Conclusion Questions: 2 Ways to weaken your argument
1) weaken or undermine one of the premises (not common on the lsat) 2) attack the conclusion directly, often by adding new information or a new premise. (Most common)
Flawed Reasoning: 7) Numbers and Percentage Errors
1) when an argument improperly equates a % with a definite quantity 2) when an argument improperly uses a quantity to determine the % represented by that quantity SEEN ON LSAT -"the author confuses the % of plastics recycled with the actual quantity of plastics recycled." -when % are used on the lsat, make sure they are used properly so you do not have a flaw in the reasoning relating to the numbers and %. EXAMPLE OF % USED INCORRECTLY -"In 2009, 30% of materials processed by Manhattan recycling plants were plastics. Early reports suggest that in 2010, that number will increase to 35%. It is clear that more plastics are being recycled." - 30% is our initial amount - the % goes up to 35%, but the total amount of plastics could have gone up or down, we don't know that info based on our argument.
Flawed Reasoning: 10) False Analogies Type 1
2 concepts, objects, or events that are proposed to be similar in nature -"A and B are similar in one way so A and B are similar in another way" Example - "bananas are yellow, the sun is yellow. Bananas weigh less than a pound, therefore, the sun weighs less than a pound."
What is a sub-conclusion?
A small conclusion along the way to your main/final conclusion. premises-support-subconclusion-support-conclusion
