Physicist: Determinism is the view that every event has a preceding cause sufficient for its occurrence. That is, if determinism is true, then the events that are presently occurring could not have failed to occur given the state of the universe a moment ago. Determinism, however, is false because it is impossible to know the complete state of the universe at any given time since it is impossible to measure accurately both the position and velocity of any given subatomic particle at a particular time.

Summarize Argument: Counter-Position
The physicist concludes that determinism (the view that every event is guaranteed by the state of the universe immediately before) is false. This is supported by the fact that it’s impossible to know the entire state of the universe at any given time. In turn, that claim is supported by the impossibility of measuring both the position and the velocity of subatomic particles at the same time.

Identify and Describe Flaw
The flaw in this argument is that the physicist mixes up the factual state of the universe with human knowledge about the state of the universe. Just because we can’t know everything about the universe at any given time, that doesn’t disprove the idea that there can be a complete and determined state of the universe.

A
That it is impossible to measure accurately both the position and velocity of any given subatomic particle does not imply that it is impossible to know either the position or velocity of all subatomic particles.
Like (C), the physicist doesn’t rely on the idea that it’s impossible to know either the position or velocity of all subatomic particles. The physicist’s point is just that we can’t know both of those things at the same time.
B
That the complete state of the universe at any given time is unknowable does not imply that the states at that time of the individual subatomic particles making it up are unknowable.
This gets the argument backwards. The physicist claims that the states of particles are unknowable to imply that the complete state of the universe is unknowable—which is totally reasonable.
C
That it is impossible to measure accurately both the position and velocity of any given subatomic particle at a particular time does not imply that its position or velocity cannot be accurately measured separately.
Like (A), this isn’t a flaw because it isn’t an assumption the physicist actually makes. The physicist’s point is that we can’t ever know both of these things at the same time. Whether we can know one or the other is irrelevant.
D
That it is impossible to know the complete state of the universe at any given time does not imply that there is no complete state of the universe at that time.
This is the flaw, because the physicist only focus on our knowledge about the universe, but draws a conclusion about the factual state of the universe. Without a link between knowledge and the factual state of the universe, the conclusion isn’t supported.
E
That the position and velocity of any given subatomic particle cannot be jointly measured with accuracy does not imply that this is the case for the position and velocity of all subatomic particles.
This just isn’t the case—if no individual particle’s position and velocity can be measured at the same time, then of course the position and velocity of all particles can’t be measured at the same time.

25 comments

Over the past 20 years, skiing has become a relatively safe sport due to improvements in ski equipment. There has been a 50 percent drop in the number of ski injuries over the last 20 years. Clearly, however, there have not been decreases in the number of injuries in all categories, as statistical data readily show, for although broken legs and ankle injuries have decreased by an astounding 90 percent, knee injuries now represent 16 percent of all ski injuries, up significantly from the 11 percent of 20 years ago.

Summarize Argument
The argument concludes that not every type of ski injury has seen decreasing numbers, although the number of ski injuries has decreased overall. This is supported with the statistic that knee injuries, which used to represent 11 percent of ski injuries, now represent 16 percent.

Identify and Describe Flaw
This is a cookie-cutter flaw of confusing amounts and percentages. The argument’s conclusion is about the amount of different types of ski injuries, but the evidence is only about percentages. However, it’s entirely possible that there are fewer knee injuries now, even though they account for a greater percentage of all ski injuries—for example, because the number of other injury types has just decreased more.

A
It fails to allow for there being ski injuries other than broken legs, ankle injuries, and knee injuries.
The argument only uses these three types of injuries as examples, it never claims that they’re the only types of ski injuries.
B
It infers disparate effects from the same single cause.
The argument is only concerned with one cause and one effect: the cause is improvements in ski equipment, and the effect is a lower number of ski injuries.
C
It ignores the possibility that the number of skiers has increased over the past 20 years.
The argument states that ski injuries have decreased by 50 percent over the past 20 years, regardless of the number of skiers. Also, the percentage statistics the argument cites are unaffected by the number of skiers.
D
It assumes that an increase in the proportion of knee injuries rules out a decrease in the number of knee injuries.
The argument concludes that certain types of injuries have not decreased in number, and uses knee injuries as an example based on an increased percentage. This ignores the possibility that there are still fewer knee injuries, even though the percentage is higher.
E
It proceeds as though there could be a greater decrease in injuries in each category of injury than there is in injuries overall.
The argument never acts as though every category of injury could see a greater decrease than the overall decrease.

26 comments

The passage provides the most support for which one of the following?

This is a Most Strongly Supported question.

Legal rules are expressed in general terms. They concern classifications of persons and actions and they prescribe legal consequences for persons and actions falling into the relevant categories.

Can you think of an example of a legal rule to help make sense of these statements?

“Robbery is the unlawful taking of property from someone else’s person through the use of force or the threat of force.”

This rule classifies certain conduct as “robbery” – the conduct of unlawfully taking property from someone else’s body or near their body through the use of force or the threat of force. If you engage in that conduct, you are committing robbery.

The application of a rule to a particular case, therefore, involves a decision on whether the facts of the case fall within the categories mentioned in the rule.

Let’s say that Ronald pushed Tracy to the ground and grabbed the scarf she was wearing. Is that robbery? We have to decide whether the facts of this situation (Ronald pushed Tracy to the ground; Ronald grabbed her scarf) belong to the category of conduct that is classified as robbery.

This decision establishes the legal effect of what happened rather than any matter of fact.

Is Ronald’s pushing of Tracy to the ground and grabbing her scarf the “unlawful taking of property from someone else’s person through the use of force or the threat of force”? I decide that it is – what Ronald did fits that category of conduct. The last sentence of the stimulus says that this decision establishes the legal effect of what Ronald did, but does not establish a matter of fact. That’s confusing. Didn’t we establish facts? E.g., that Ronald pushed Tracy to the ground and grabbed her scarf. Yes, but that’s not what “this decision” is referring to. We did not decide that Ronald pushed Tracy to the ground. Ronald just pushed Tracy to the ground. So take a moment to see if you can identify the target of the referential “this decision.”

“This decision” refers to the “decision on whether the facts of the case fall within the categories mentioned in the rule.” In other words, it refers to our decision to label Ronald’s push as a “use of force.” That decision is not a matter of fact. Rather, it’s a legal conclusion. Similarly, labeling Ronald’s grabbing of Tracy’s scarf a “taking of property from someone else’s person” is not a matter of fact, but a claim about the legal effect of Ronald’s action.

The stimulus isn’t structured to lead to a particular conclusion that we should anticipate. So let’s just dive in and pick the answer that’s most supported.

Answer Choice (A) Legal rules, like matters of fact, are concerned with classifications of things such as actions.

It might be fair to say that legal rules are concerned with classifications of things such as actions. We know from the second sentence that legal rules are concerned with classifications of persons and actions, so we can say that legal rules are concerned with classifying actions (although not exclusively).

But when (A) says “like matters of fact,” that means (A) is asserting that matters of fact are also concerned with classifications of things such as actions. We don’t know from the stimulus whether matters of fact are about classifying actions. We don’t have any statements suggesting what matters of fact are concerned with.

A better version of (A) might go something like this: Legal rules, unlike matters of fact, are concerned with classifications of things such as actions.

Answer Choice (B) Matters of fact, like legal rules, can sometimes be expressed in general terms.

We know that legal rules can be expressed in general terms from the first sentence. But the stimulus doesn’t say whether matters of fact can be expressed in general terms.

Answer Choice (C) Making a legal decision does not involve matters of fact.

(C) is anti-supported. The correct version of (C) would actually say the opposite: Making a legal decision does involve matters of fact.

But (C) is tempting, because we know that the “decision on whether the facts of [a] case fall within the categories [of a] rule” does not “establish” a matter of fact. But that’s different from whether the decision involves a matter of fact.

The decision that Ronald’s pushing of Tracy was a “use of force” does not establish any fact – it established instead a legal effect of his pushing.

But the decision that Ronald’s pushing of Tracy was a “use of force” did involve a fact – it involves the fact that he pushed her.

Answer Choice (D) The application of a rule to a particular case need not be left to a judge.

(D) might be tempting if you’re thinking about what’s true in the real world – of course other people besides judges can apply rules. You’re applying rules all over the LSAT! But the stimulus doesn’t suggest anything about judges or about who can or cannot apply a rule.

Correct Answer Choice (E) Whether the facts of a case falls into a relevant category is not itself a matter of fact.

This is the more roundabout way of saying what our corrected version of (C) says. To reiterate, whether Ronald’s pushing of Tracy was a use of force involves a matter of fact (the fact that he pushed her), but it does not establish a matter of fact. If we decide that Ronald’s action does constitute a “use of force,” that decision, according to the last sentence of the stimulus, is not a fact. It is instead a claim about the legal effect of what he did.


92 comments