Self-study
Doctor: The patient had been experiencing back and leg pain. █ ████████████ ████ █████████ ████ █████ ███ ████████ ██ █ █████ ███████ ██ ███ ███ ████ █ █████ █████████ ████ ████████ ███ █████ █████ █████████████ █████ ███ ██ ████ █████ █████ █ ███████ ████ ██ ███ █████ ███ █████████ ███ ████ ███ ██ ██████ ███ ████████████ █████ ██ █ █████████ █████████ ██ ███ ██████ ███ █████ ██ █████ ███ ██████ ██ ███████████ ████ ███████ █ █████████ ██████████ ████ ████████ ██ ███ █████ ██ ████████ ███ ███████ ████ █████████ ████ ███ ███ █████
Summary
The author concludes that pressure on a certain nerve was causing the patient’s back and leg pain.
Why?
Because a computer scan provided evidence of pressure on that nerve. Pressure can cause inflammation, which can cause pain.
Moreover, if there was nerve inflammation, a cortisone injection would reduce inflammation.
After administering a cortisone injection, the patient experienced reduced pain.
Notable Assumptions
The author assumes that there’s no other reason the patient could have had reduced pain following the cortisone injection other than the injection’s ability to reduce pressure on the nerve. (This overlooks the possibility that the injection might have helped reduce pain by relieving some other aspect of the patient’s body, such as a different nerve or muscle.)
19.
Which one of the following ██ ██ ██████████ ████████ ██ ███ ████████ █████████
a
Computerized scans are ███ ████ ████████ ███ ██ ██████████ ███████ █████ ██ █████████
Not necessary, because computer scans can still provide some evidence of the cause of pain even if they are not the most accurate.
b
The cortisone injection ███ ███ ██████ ████████ ██ ███ ████████ █████ ██ ███ █████████ ████
Not necessary, because the negation would strengthen the argument. If the injection DID reduce pressure on the inflamed nerve in the patient’s leg, that’s evidence the pressure may have been the cause of the pain.
c
The pain relief ███ ███ █████ ██████ ███████ ███ █████████ ██████ ██ ███ ████████ ██ ███ ██████████
Necessary, because if it were not true — if the pain relief DID occur merely through the belief that the cortisone would be effective — then that would mean the injection did not actually reduce any inflammation or relieve any pressure. And in that case, we’d have no reason to think that the patient’s improvement following the injection is evidence that the pain was caused by pressure on the nerve.
d
Only cortisone injections ███ █████ █ █████████ ██ ██ ████████████ ██ █ █████ ████ ████ ██ ███ █████████ ████
Not necessary, because even if there are other things in addition to the injection that can reduce inflammation, we still know that the injection was used and that it might have reduced inflammation in this case. The argument’s reasoning only requires that the injection be ONE of the things that can reduce inflammation.
e
The best treatment ███ ████ ███ ███ ████ ██ ███████ █ ████ ████ ████████ █████████████
Not necessary, because the course of treatment the patient received can still provide evidence of that nerve pressure caused the pain even if that treatment wasn’t the “best” available.