Wounds become infected because the break in the skin allows bacteria to enter. Infection slows healing. Often bacteria-killing ointment is applied to wounds after they have been cleaned, but a study at a Nigerian hospital found that cleaned wounds that were treated with honey—which contains significant quantities of bacteria—healed faster, on average, than both cleaned wounds treated with antibiotic ointment and wounds cleaned but not otherwise treated.

"Surprising" Phenomenon
Why did cleaned wounds treated with honey heal faster than both cleaned wounds treated with antibiotics and wounds that were only cleaned, even though honey has lots of bacteria, which slows healing?

Objective
The correct answer should tell us something that suggests the net effect of honey on healing time results in faster healing than cleaning wounds with antibiotics and cleaning wounds without additional substances. For example, there could be something in honey that kills enough bacteria to offset the additional bacteria in honey such that honey-treated wounds end up with less bacteria than antibiotics-treated wounds.

A
Wounds that have simply been cleaned with soap and water and not otherwise treated heal faster than wounds that have been cleaned and then treated with antibiotic ointment.
This doesn’t explain why the honey-treated wounds healed faster. And, we have no reason to think the cleaned wounds were cleaned with soap and water (as opposed to just water, or something else).
B
The bacteria found in honey are present in much lower concentrations than the concentrations of bacteria typically present in infected wounds, and applying antibiotic ointment to a wound rarely if ever kills all of the bacteria infecting the wound.
Even if the honey-bacteria has a lower concentration than wound-bacteria, the honey-treated wound would still have both the honey-bacteria and the regular wound-bacteria. So we’d still expect it to have more bacteria than an antibiotic-treated wound.
C
Honey has properties that inhibit the growth of bacteria in wounds, including the bacteria the honey contains, and antibiotic ointments damage sensitive wound tissue, which slows healing.
So, honey stops bacteria growth, including its own bacteria. And, on top of that, antibiotics do something that slows healing. This provides a potential explanation for why honey-treated wounds healed the fastest.
D
The high concentration of sugar in honey inhibits the growth of bacteria in wounds, including the bacteria contained in the honey itself.
(D) only explains why honey is better than cleaning alone. It doesn’t explain why honey-treated wounds healed faster than the antibiotic-treated wounds. After all, we’d expect antibiotics to kill bacteria, too.
E
The antibiotic ointment used in the study damages sensitive tissue in wounds, which slows healing, but honey does not have this effect if the wound has been cleaned.
So, honey has one advantage over antibiotic ointment. You know what else it has? Tons of bacteria. This doesn’t help explain why honey-treated wounds, in light of that bacteria, healed faster than antibiotic-treated wounds.

5 comments

One should not do anything that has the potential to produce serious harm to one’s society. The public actions—or inactions—of celebrities and of people who are widely respected are widely emulated. Some celebrities do not vote. Serious harm befalls a society in which many people refrain from voting.

Summary
If an action has the potential to produce serious harm to one’s society, then one should not take that action.

Many people copy the public actions of celebrities and those who are widely respected.

Some celebrities do not vote.

Serious harm comes to societies in which many people don’t vote.

Notable Valid Inferences
Celebrities shouldn’t publicly refrain from voting.

Widely respected people shouldn’t refrain from voting.

A
A society should require all celebrities to vote.
Could be false. The stimulus discusses what actions individuals should not take; the stimulus does not discuss what society should require.
B
One should vote only if one expects that doing so will cause many other people to do likewise.
Could be false. (B) gives a necessary condition for when you should vote. The stimulus doesn’t allow us to infer any necessary conditions for voting.
C
Celebrities who do not vote should not be widely respected.
Could be false. The stimulus doesn’t give any indication on who should or should not be widely respected.
D
People should not emulate celebrities who are not widely respected.
Could be false. The stimulus doesn’t indicate who people should nor should not emulate. Additionally, we only know that people who are widely respected are widely emulated. We don’t know anything about people who aren’t widely respected.
E
Widely respected people should not publicly refrain from voting.
Must be true. If an action could cause serious harm to society, then one shouldn’t take that action. Widely respected people’s public actions are widely emulated, and society is harmed when many people don’t vote, so widely respected people shouldn’t publicly refrain from voting.

10 comments

Bernard: We should not invite Carl to speak at the forum. Carl’s views are clearly false, and worse, dangerous. To encourage their consideration will not only legitimize them but also help to promulgate them, both of which we should avoid, since we wish not to support their adoption.

Ayla: The best way to combat false views is to challenge them in public. Once Carl’s views are subjected to the kind of public scrutiny the forum provides, people will see them for what they are because the forum will provide convincing arguments against them.

Speaker 1 Summary
Bernard concludes we shouldn’t invite Carl to speak at the forum. This is because Carl’s views are false and dangerous. We don’t want to support adoption of those views, and inviting him to speak would help spread those views.

Speaker 2 Summary
Ayla’s implicit conclusion is that we should invite him to speak. This is because challenging his views in public is the best way to combat them.

Objective
We’re looking for a disagreement. The speakers disagree about whether we should invite Carl to the forum.

A
one should always avoid legitimizing a view whose adoption one wishes not to support
Ayla doesn’t have an opinion. Although she wants to challenge Carl’s false views, we don’t know what she thinks about views she wishes not to support. She might think it’s OK to legitimize views she doesn’t support, as long as they’re not false.
B
people will see the falsity of every dangerous idea for which they are furnished with forceful counterarguments
Bernard doesn’t have an opinion. He doesn’t discuss what happens when people encounter counterarguments against views.
C
the best way to fight erroneous ideas involves allowing the public expression of these ideas
The speakers disagree. Bernard implicitly thinks this is not the best way, because he says not to invite Carl. If he thought this was the best way to fight Carl’s ideas, he wouldn’t make this recommendation. Ayla thinks the best way to fight Carl’s ideas is to allow him to speak.
D
people who hold false views tend to pose a danger to society
Ayla doesn’t have an opinion. She doesn’t discuss the idea of danger or whether some views can be dangerous.
E
one should not encourage the adoption of dangerous views
Ayla doesn’t have an opinion. She doesn’t discuss the idea of danger or whether we should encourage adoption of dangerous views.

1 comment

News report: Some recently invented television screens are built out of small tiles seamlessly joined together, each tile a separate miniature screen. Television sets with these compound screens are just a few inches thick. For a noncompound screen in a set of this thickness, the larger the screen is, the dimmer it is. However, each tile in a compound screen is small enough to be quite bright. Moreover, an unlimited number of the tiles can be joined together, without making the resulting screen any less bright or the set any thicker.

Summary

Compound television screens are built by joining together small tiles that are each a separate miniature screen.

TVs with compound screens are just a few inches thick.

When the thickness of TVs with noncompound screens is held constant, the larger a screen is, the dimmer it is.

Each tile in a compound screen is small enough to retain brightness.

In compound screens, you can have an unlimited number of tiles joined together without making the screen less bright or the TV set thicker.

Notable Valid Inferences

For TVs with compound screens, having a larger screen doesn’t mean that the screen will be dimmer. These TVs can be bright and large.

A
The technology used to make compound television screens is not appropriate for television sets with relatively small screens.

Could be false. There is no information in the stimulus to indicate that compound screens can’t be used for TVs with small screens.

B
There is a great consumer demand for television sets that are just a few inches thick and that have very large screens.

Could be false. The stimulus does not mention consumer demand, so we cannot make inferences about consumer demand.

C
In a television set with a noncompound screen, the thicker the television set, the brighter the screen.

Could be false. The stimulus only discusses noncompound screens “in a set of this thickness.” The stimulus does not discuss how changing the thickness of the TV impacts the brightness of the screen.

D
Television sets that are just a few inches thick can now be made with screens that are both bright and very large.

Must be true. TVs with compound screens are just a few inches thick, and they can have screens that are both bright and very large.

E
Television sets with compound screens do not have any disadvantages relative to sets with noncompound screens.

Could be false. This is outside of the scope of the stimulus; it could certainly be the case that there are many disadvantages of TVs with compound screens that the stimulus did not mention.


7 comments

Orator: Moral excellence can be achieved only by repeatedly overcoming inclinations to do the wrong thing. Overcoming these inclinations is often difficult to do, even for a morally virtuous person, but the only way to become a morally virtuous person is through the achievement of moral excellence.

Summary

The stimulus can be diagrammed as follows:

Notable Valid Inferences

If one is morally virtuous, then one has repeatedly overcome inclinations to do wrong.

A
A morally virtuous person is incapable of doing the wrong thing.

Must be false. All morally virtuous people have overcome the inclination to do the wrong thing, which means that these people are capable of doing the wrong thing––they just overcame the urge to do so.

B
Most people who achieve moral excellence are morally virtuous.

Could be false. We know that all people who become morally virtuous achieve moral excellence, but we don’t know what quantity of people who achieve moral excellence are morally virtuous.

C
Someone who has no inclination to do anything that is wrong has achieved moral excellence.

Could be false. The stimulus discusses those who have repeatedly overcome inclinations to do the wrong thing, not those who have no inclination to do the wrong thing. These are different ideas.

D
Someone who is not morally virtuous is incapable of achieving moral excellence.

Could be false. We know that all people who become morally virtuous achieve moral excellence. (D) confuses the sufficient and necessary conditions in this relationship.

E
Every morally virtuous person has been inclined to do something that is wrong.

Must be true. We know that all morally virtuous people have repeatedly overcome the inclinations to do something wrong, which means that they have faced this inclination before.


6 comments