Additional Premise and Counter-Premise Recognition

 Mini-Drill Answer Key
1. Features the counter-premise indicator “however” and the premise indicator
“since.”
Premise: “Wine is made by crushing grapes and eventually separating
the juice from the grape skins.”
Counter-premise: “However, the separated juice contains impurities
and many wineries do not filter the juice.”
Premise: “These wineries claim the unfiltered juice ultimately
produces a more flavorful and intense wine.”
Premise: “Since these wine makers are experts,”
Conclusion: “we should trust their judgment and not shy away from
unfiltered wine.”
2. Features the additional premise indicator “in addition” and the conclusion
indicator “hence.” In this problem the additional premise is central to
supporting the conclusion.
Premise: “Phenylketonurics are people who cannot metabolize the
amino acid phenylalanine.”
Premise: “There are dangers associated with phenylketonuria, and
products containing phenylalanine must carry a warning label
that states, ‘Phenylketonurics: contains phenylalanine.’ ”
Additional Premise: “In addition, all children in developed societies
received a phenylketonuria test at birth.”
Conclusion: “Hence, at the moment, we are doing as much as possible
to protect against this condition.”
3. Features the counter-premise indicator “despite”; the additional premise
indicator “after all”; and the conclusion indicator “thus.” The additional
premise serves to downplay the counter-premise.
Premise: “During last night’s robbery, the thief was unable to open the
safe.”
Counter-premise: “despite the fact that the thief stole several
documents.”
Additional Premise: “After all, nothing in those documents was as
valuable as the money in the safe.”
Conclusion: “Thus, last night’s robbery was unsuccessful ”

Additional Premise and Counter-Premise Recognition Mini-Drill

Each of the following problems contains a short argument. For each argument,
identify the conclusion, the premise(s), and any additional premises or
counter-premises. Answers on the next page.
1. Wine is made by crushing grapes and eventually separating the juice
from the grape skins. However, the separated juice contains impurities
and many wineries do not filter the juice. These wineries claim the
unfiltered juice ultimately produces a more flavorful and intense wine.
Since these wine makers are experts, we should trust their judgment
and not shy away from unfiltered wine.
2. Phenylketonurics are people who cannot metabolize the amino acid
phenylalanine. There are dangers associated with phenylketonuria, and
products containing phenylalanine must carry a warning label that
states, “Phenylketonurics: contains phenylalanine.” In addition, all
children in developed societies receive a phenylketonuria test at birth.
Hence, at the moment, we are doing as much as possible to protect
against this condition.
3. During last night’s robbery, the thief was unable to open the safe. Thus,
last night’s robbery was unsuccessful despite the fact that the thief
stole several documents. After all, nothing in those documents was as
valuable as the money in the safe.

Additional Premise Indicators

Aside from previously listed premise and conclusions indicators, there are
other argument indicator words you should learn to recognize. First, in
argument forms, sometimes the author will make an argument and then for
good measure add another premise that supports the conclusion but is
sometimes non-essential to the conclusion. These are known as additional
premises:
Additional Premise Indicators
Furthermore
Moreover
Besides
In addition
What’s more
Following are two examples of additional premise indicators in use:
1. “Every professor at Fillmore University teaches exactly one class
per semester. Fillmore’s Professor Jackson, therefore, is teaching
exactly one class this semester. Moreover, I heard Professor Jackson
say she was teaching only a single class.”
The first sentence is a premise. The second sentence contains
the conclusion indicator “therefore” and is the conclusion of the
argument. The first sentence is the main proof offered by the
author for the conclusion. The third sentence begins with the
additional premise indicator “moreover.” The premise in this
sentence is non-essential to the argument, but provides
additional proof for the conclusion and could be, if needed,
used to help prove the conclusion separately (this would occur
if an objection was raised to the first premise).
2. “The city council ought to ease restrictions on outdoor advertising
because the city’s economy is currently in a slump. Furthermore, the
city should not place restrictions on forms of speech such as
advertising.”
The first sentence contains both the conclusion of the argument
and the main premise of the argument (introduced by the
premise indicator “because”). The last sentence contains the
additional premise indicator “furthermore.” As with the
previous example, the additional premise in this sentence is
non-essential to the argument but provides additional proof for
the conclusion.