Assumptions

[pacer]

I want to clarify something about assumptions with regards to prescriptive statements that contain words like should, will etc.

If I make a prescriptive statement or recommendation such as

Nurses should not work at night

Is it fair to say that I am making an assumption that there is no need/reason for nurses to work at night? That in fact, it is possible for nurses to listen to my recommendation and stop working at night?

So for an assumption question, the answer should negate any possible reasons for nurses having to work at night. And for a flaw question, the answer should state "The author assumes/presumes, without justification that nurses have no reason for working at night"


Another example:

A doctor prescribes expensive antibiotics to a patient.

The doctor is assuming that the patient has the money to buy the antibiotics, and that there is no other reasons for the patient not taking the antibiotics.

I think I am getting confused in terms of what happens in our daily lives versus what holds true on the LSAT.

In real life, we make lots of prescriptive statements or recommendations to others or about something but we don't necessarily weigh all the factors needed to actually fulfill those recommendations when we make them in our daily lives.


On the LSAT, for such statement that make prescriptions/recommendations, the assumption is that it is in fact possible to fulfill such recommendations?

Another example -

You should promote your business on facebook to help boost sale. Most people today have facebook accounts and greatly rely on social media to make purchasing decisions.

Is it correct to say that the author is assuming that promoting a business via facebook does in fact leads to a boost in sales? Or does the assumption need to make a link between purchasing decisions and facebook/boost sales?


I have gone through the assumptions question type chapter in the book twice but I still seem to missing out on a lot of the assumption questions. Any tips/advice?

[Nikki Siclunov]

Hi pacer,

Good question! It is very important not to mix up the layman's version of what an "assumption" is with the logical meaning of the term "assumption." The latter is this: an unstated premise that must be true for the conclusion to be logically valid. Let's look at the examples you give:

If I make a prescriptive statement or recommendation such as

Nurses should not work at night

Is it fair to say that I am making an assumption that there is no need/reason for nurses to work at night? That in fact, it is possible for nurses to listen to my recommendation and stop working at night?

So for an assumption question, the answer should negate any possible reasons for nurses having to work at night. And for a flaw question, the answer should state "The author assumes/presumes, without justification that nurses have no reason for working at night"

No, the author does not presume that nurses have no reason to work at night. They might have some reason to do so, and their reasons may actually be quite valid. But in the aggregate, the reasons against working at night must outweigh the reasons for working at night. Prescriptive conclusions do not presume the absence of any objections to their prescriptions. Rather, they assume that whatever objections there may be are outweighed by the benefits of following the prescription. The assumption of a cost/benefit outcome is a lot more subtle, and is frequently tested on the LSAT.

Another example:

A doctor prescribes expensive antibiotics to a patient.

The doctor is assuming that the patient has the money to buy the antibiotics, and that there is no other reasons for the patient not taking the antibiotics.

The author is not making any assumption regarding the patient's ability to pay. Even if the patient is unable to pay for the medication, it is still possible that it was properly prescribed. The assumption is that whatever costs the patient will incur (monetary costs, side effects, etc.) will be outweighed by the benefits of taking the medication.

You should promote your business on Facebook to help boost sale. Most people today have Facebook accounts and greatly rely on social media to make purchasing decisions.

Is it correct to say that the author is assuming that promoting a business via Facebook does in fact leads to a boost in sales? Or does the assumption need to make a link between purchasing decisions and facebook/boost sales?

The author is assuming that promoting a business via Facebook can sometimes lead to a boost in sales. The causal link is assumed, but it need not be an absolute, conditional relationship. Why? Because even if the recommended course of action doesn't always lead to a boost in sales (the logical opposite of an absolute relationship), this would not immediately invalidate the conclusion that *I* should promote my business on Facebook.

Remember: assumptions are very carefully tailored statements that do not go beyond the scope of the argument. In many ways, they are similar to Must Be True answers: both can be proven by reference to the stimulus at hand. In most of the examples you gave, the statement you made strengthened the conclusion, but was not something required by it.

Thanks!