Critical Reasoning - Comunication Skills

: Critical Reasoning - Comunication Skills

Created by: Nidhi Chandel
 Page 1


© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 1 
CRITICAL REASONING 101 
 
wo guys are looking at a glass filled to half its capacity. One guy 
reaches the conclusion that the “glass is half full” and the other guy 
reaches the conclusion that the “glass is half empty”.  This story, in a 
nutshell, encapsulates what an ‘interpretation of evidence’ is all about.  In 
this instance, notice that the two so-called different interpretations have 
the SAME significance and the interpretations will qualify as ‘logical 
interpretations’.  On the other hand, if the person looking at the glass  filled 
to half its capacity were to reach the conclusion that ‘someone forgot to fill 
the entire glass’ or that ‘someone did not finish drinking all the liquid in the 
glass’, the person will be ‘guilty’ of making an ILLOGICAL CONCLUSION. 
 
An ILLOGICAL CONCLUSION is one that is derived on the basis of the 
stated EVIDENCE and on the basis of additional information TAKEN FOR 
GRANTED. The additional information taken for granted is the 
ASSUMPTION of the argument. In the first case, the persons reaching the 
conclusion that ‘the glass is half full or half empty’ did not bring in 
additional information into the argument in order to reach a conclusion. 
Therefore, the persons reaching the conclusion were ‘logical’ in their 
interpretation of the evidence. However, in the second case, the person 
looking at the same evidence ‘assumed’ or ‘took for granted’ that the ‘liquid 
in the glass could not have evaporated or spilled out, or could not have 
been drunk by the drinking bird’. (Therefore, the person forgot to fill it to 
the brim or forgot to drink all of it.) 
 
An ARGUMENT is essentially the conclusion of a line of reasoning using an evidentiary 
basis and additional information either taken for granted or not considered at all.  The 
EVIDENCE provides the CONTEXT for the Conclusion, and is critical to the conclusion.  
The conclusion of an argument taken alone is without context and may not shed light on 
the WHY of the conclusion. 
 
All information needs to be processed in terms of two questions:  WHAT is being said? 
And Why is it being said?  The conclusion answers ‘WHAT’ is being said whereas the 
evidence answers “WHY” the conclusion is being said. If the conclusion is that the ‘use of 
marijuana can cause cancer’, the basis or the context for this conclusion is that ‘an 
ingredient called THC inactivates the herpes virus that can trigger the uncontrolled growth 
of cancer cells’, we need to process both the WHAT and WHY of the argument.  
 
The test is about your ability to process information in context and to understand the 
question that relates to the argument in order that you pick an answer choice that is 
relevant to the specific scope of information that is presented to you and to the question 
posed to you. 
 
Do not process information in vague generalities. For example, the above argument about 
marijuana cannot be processed as ‘something about marijuana being bad’.  Process the 
specifics and deal with the question on that basis. 
 
 
T
Page 2


© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 1 
CRITICAL REASONING 101 
 
wo guys are looking at a glass filled to half its capacity. One guy 
reaches the conclusion that the “glass is half full” and the other guy 
reaches the conclusion that the “glass is half empty”.  This story, in a 
nutshell, encapsulates what an ‘interpretation of evidence’ is all about.  In 
this instance, notice that the two so-called different interpretations have 
the SAME significance and the interpretations will qualify as ‘logical 
interpretations’.  On the other hand, if the person looking at the glass  filled 
to half its capacity were to reach the conclusion that ‘someone forgot to fill 
the entire glass’ or that ‘someone did not finish drinking all the liquid in the 
glass’, the person will be ‘guilty’ of making an ILLOGICAL CONCLUSION. 
 
An ILLOGICAL CONCLUSION is one that is derived on the basis of the 
stated EVIDENCE and on the basis of additional information TAKEN FOR 
GRANTED. The additional information taken for granted is the 
ASSUMPTION of the argument. In the first case, the persons reaching the 
conclusion that ‘the glass is half full or half empty’ did not bring in 
additional information into the argument in order to reach a conclusion. 
Therefore, the persons reaching the conclusion were ‘logical’ in their 
interpretation of the evidence. However, in the second case, the person 
looking at the same evidence ‘assumed’ or ‘took for granted’ that the ‘liquid 
in the glass could not have evaporated or spilled out, or could not have 
been drunk by the drinking bird’. (Therefore, the person forgot to fill it to 
the brim or forgot to drink all of it.) 
 
An ARGUMENT is essentially the conclusion of a line of reasoning using an evidentiary 
basis and additional information either taken for granted or not considered at all.  The 
EVIDENCE provides the CONTEXT for the Conclusion, and is critical to the conclusion.  
The conclusion of an argument taken alone is without context and may not shed light on 
the WHY of the conclusion. 
 
All information needs to be processed in terms of two questions:  WHAT is being said? 
And Why is it being said?  The conclusion answers ‘WHAT’ is being said whereas the 
evidence answers “WHY” the conclusion is being said. If the conclusion is that the ‘use of 
marijuana can cause cancer’, the basis or the context for this conclusion is that ‘an 
ingredient called THC inactivates the herpes virus that can trigger the uncontrolled growth 
of cancer cells’, we need to process both the WHAT and WHY of the argument.  
 
The test is about your ability to process information in context and to understand the 
question that relates to the argument in order that you pick an answer choice that is 
relevant to the specific scope of information that is presented to you and to the question 
posed to you. 
 
Do not process information in vague generalities. For example, the above argument about 
marijuana cannot be processed as ‘something about marijuana being bad’.  Process the 
specifics and deal with the question on that basis. 
 
 
T
© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 2 
 
LOGICAL REASONING 101 
 
Deductive and Inductive Arguments 
 
Logical Reasoning involves two types are arguments: Deductive 
and Inductive. 
 
A deductive argument is an argument in if the 
premises (generally explicitly stated) are true, it would 
be impossible for the conclusion to be false. In order 
words, if the evidence is true, then the conclusion is 
necessarily true or the conclusion MUST BE TRUE. 
Deductive reasoning will be tested in verbal context 
(in the LSAT) and in the verbal and quantitative 
context in the other two graduate school tests – 
GMAT and GRE.  
 
An inductive argument is an argument in which the 
evidence used is such that the conclusion that is 
reached on the basis of the premises (explicit and 
implied) is merely PROBABLE, not CERTAIN.  All 
three tests – LSAT, GRE, and GMAT – will ask you to 
identify arguments in which the conclusion is merely 
one of several probable scenarios consistent with the 
evidence.  The Argument essays tested on all three 
tests are about your ability to identify OTHER equally 
probable conclusions that are consistent with the 
evidence.  GMAT and GRE will also test your ability to 
test more than ONE PROBABLE interpretation of the 
evidence and to see whether the conclusion that can 
reached on this basis is consistent across different 
scenarios consistent with the evidence.  
 
Because deductive arguments (also referred to as 
Logical Conclusions on the three tests) are those in 
which the truth of the conclusion is thought to be 
completely guaranteed and not just made 
probable by the truth of the premises (usually explicit 
or necessarily implied in the explicit information). In 
such arguments, the truth of the conclusion is 
"contained within" the truth of the premises; i.e., 
the conclusion does not go beyond what the truth of 
the premises implicitly requires. For this reason, 
Page 3


© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 1 
CRITICAL REASONING 101 
 
wo guys are looking at a glass filled to half its capacity. One guy 
reaches the conclusion that the “glass is half full” and the other guy 
reaches the conclusion that the “glass is half empty”.  This story, in a 
nutshell, encapsulates what an ‘interpretation of evidence’ is all about.  In 
this instance, notice that the two so-called different interpretations have 
the SAME significance and the interpretations will qualify as ‘logical 
interpretations’.  On the other hand, if the person looking at the glass  filled 
to half its capacity were to reach the conclusion that ‘someone forgot to fill 
the entire glass’ or that ‘someone did not finish drinking all the liquid in the 
glass’, the person will be ‘guilty’ of making an ILLOGICAL CONCLUSION. 
 
An ILLOGICAL CONCLUSION is one that is derived on the basis of the 
stated EVIDENCE and on the basis of additional information TAKEN FOR 
GRANTED. The additional information taken for granted is the 
ASSUMPTION of the argument. In the first case, the persons reaching the 
conclusion that ‘the glass is half full or half empty’ did not bring in 
additional information into the argument in order to reach a conclusion. 
Therefore, the persons reaching the conclusion were ‘logical’ in their 
interpretation of the evidence. However, in the second case, the person 
looking at the same evidence ‘assumed’ or ‘took for granted’ that the ‘liquid 
in the glass could not have evaporated or spilled out, or could not have 
been drunk by the drinking bird’. (Therefore, the person forgot to fill it to 
the brim or forgot to drink all of it.) 
 
An ARGUMENT is essentially the conclusion of a line of reasoning using an evidentiary 
basis and additional information either taken for granted or not considered at all.  The 
EVIDENCE provides the CONTEXT for the Conclusion, and is critical to the conclusion.  
The conclusion of an argument taken alone is without context and may not shed light on 
the WHY of the conclusion. 
 
All information needs to be processed in terms of two questions:  WHAT is being said? 
And Why is it being said?  The conclusion answers ‘WHAT’ is being said whereas the 
evidence answers “WHY” the conclusion is being said. If the conclusion is that the ‘use of 
marijuana can cause cancer’, the basis or the context for this conclusion is that ‘an 
ingredient called THC inactivates the herpes virus that can trigger the uncontrolled growth 
of cancer cells’, we need to process both the WHAT and WHY of the argument.  
 
The test is about your ability to process information in context and to understand the 
question that relates to the argument in order that you pick an answer choice that is 
relevant to the specific scope of information that is presented to you and to the question 
posed to you. 
 
Do not process information in vague generalities. For example, the above argument about 
marijuana cannot be processed as ‘something about marijuana being bad’.  Process the 
specifics and deal with the question on that basis. 
 
 
T
© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 2 
 
LOGICAL REASONING 101 
 
Deductive and Inductive Arguments 
 
Logical Reasoning involves two types are arguments: Deductive 
and Inductive. 
 
A deductive argument is an argument in if the 
premises (generally explicitly stated) are true, it would 
be impossible for the conclusion to be false. In order 
words, if the evidence is true, then the conclusion is 
necessarily true or the conclusion MUST BE TRUE. 
Deductive reasoning will be tested in verbal context 
(in the LSAT) and in the verbal and quantitative 
context in the other two graduate school tests – 
GMAT and GRE.  
 
An inductive argument is an argument in which the 
evidence used is such that the conclusion that is 
reached on the basis of the premises (explicit and 
implied) is merely PROBABLE, not CERTAIN.  All 
three tests – LSAT, GRE, and GMAT – will ask you to 
identify arguments in which the conclusion is merely 
one of several probable scenarios consistent with the 
evidence.  The Argument essays tested on all three 
tests are about your ability to identify OTHER equally 
probable conclusions that are consistent with the 
evidence.  GMAT and GRE will also test your ability to 
test more than ONE PROBABLE interpretation of the 
evidence and to see whether the conclusion that can 
reached on this basis is consistent across different 
scenarios consistent with the evidence.  
 
Because deductive arguments (also referred to as 
Logical Conclusions on the three tests) are those in 
which the truth of the conclusion is thought to be 
completely guaranteed and not just made 
probable by the truth of the premises (usually explicit 
or necessarily implied in the explicit information). In 
such arguments, the truth of the conclusion is 
"contained within" the truth of the premises; i.e., 
the conclusion does not go beyond what the truth of 
the premises implicitly requires. For this reason, 
© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 3 
deductive arguments are usually limited to inferences 
that follow from literal interpretation of the evidence 
and from universal definitions relied upon in  
mathematics and other rules of formal logic.  
 
For example, the following are deductive arguments 
in which the conclusion is necessarily true if the 
premises used as evidence are true:  
 
There are 120 people in the class, taking either 
English or Spanish language courses, and no person 
takes both courses. 80 people take English language 
courses. Therefore, there are 40 students taking 
Spanish language courses.   
 
Each year, the official estimate of the available cod in 
the Atlantic is made on the basis of an AVERAGE of 
the two estimates:  the official tonnage of cods caught 
by research vessels and the commercial tonnage of 
cods caught by other fishing vessels.  In the past, the 
two tonnages agreed were within 1% of each other. 
However, in the past, the official tonnage went 
markedly down by the same amount as the 
commercial tonnage went up.  Therefore, the official 
estimate remained practically unaffected.  
 
Notice that because the average is computed by 
adding up the two estimates and dividing the sum by 
2, if one of the values goes up by about the SAME 
amount as the other went down, then the sum of the 
two tonnages should remain the same and the 
average will remain unaffected.  The conclusion 
stated is a valid DEDUCTION and necessarily true. 
 
Inductive arguments or ILLOGICAL ARGUMENTS, 
on the other hand, can appeal to any consideration 
that might be thought relevant to the probability 
of the truth of the conclusion. Inductive arguments, 
therefore, can take very wide ranging forms, including 
arguments dealing with statistical data, 
generalizations from past experience, appeals to 
signs, evidence or authority, and causal relationships.  
Page 4


© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 1 
CRITICAL REASONING 101 
 
wo guys are looking at a glass filled to half its capacity. One guy 
reaches the conclusion that the “glass is half full” and the other guy 
reaches the conclusion that the “glass is half empty”.  This story, in a 
nutshell, encapsulates what an ‘interpretation of evidence’ is all about.  In 
this instance, notice that the two so-called different interpretations have 
the SAME significance and the interpretations will qualify as ‘logical 
interpretations’.  On the other hand, if the person looking at the glass  filled 
to half its capacity were to reach the conclusion that ‘someone forgot to fill 
the entire glass’ or that ‘someone did not finish drinking all the liquid in the 
glass’, the person will be ‘guilty’ of making an ILLOGICAL CONCLUSION. 
 
An ILLOGICAL CONCLUSION is one that is derived on the basis of the 
stated EVIDENCE and on the basis of additional information TAKEN FOR 
GRANTED. The additional information taken for granted is the 
ASSUMPTION of the argument. In the first case, the persons reaching the 
conclusion that ‘the glass is half full or half empty’ did not bring in 
additional information into the argument in order to reach a conclusion. 
Therefore, the persons reaching the conclusion were ‘logical’ in their 
interpretation of the evidence. However, in the second case, the person 
looking at the same evidence ‘assumed’ or ‘took for granted’ that the ‘liquid 
in the glass could not have evaporated or spilled out, or could not have 
been drunk by the drinking bird’. (Therefore, the person forgot to fill it to 
the brim or forgot to drink all of it.) 
 
An ARGUMENT is essentially the conclusion of a line of reasoning using an evidentiary 
basis and additional information either taken for granted or not considered at all.  The 
EVIDENCE provides the CONTEXT for the Conclusion, and is critical to the conclusion.  
The conclusion of an argument taken alone is without context and may not shed light on 
the WHY of the conclusion. 
 
All information needs to be processed in terms of two questions:  WHAT is being said? 
And Why is it being said?  The conclusion answers ‘WHAT’ is being said whereas the 
evidence answers “WHY” the conclusion is being said. If the conclusion is that the ‘use of 
marijuana can cause cancer’, the basis or the context for this conclusion is that ‘an 
ingredient called THC inactivates the herpes virus that can trigger the uncontrolled growth 
of cancer cells’, we need to process both the WHAT and WHY of the argument.  
 
The test is about your ability to process information in context and to understand the 
question that relates to the argument in order that you pick an answer choice that is 
relevant to the specific scope of information that is presented to you and to the question 
posed to you. 
 
Do not process information in vague generalities. For example, the above argument about 
marijuana cannot be processed as ‘something about marijuana being bad’.  Process the 
specifics and deal with the question on that basis. 
 
 
T
© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 2 
 
LOGICAL REASONING 101 
 
Deductive and Inductive Arguments 
 
Logical Reasoning involves two types are arguments: Deductive 
and Inductive. 
 
A deductive argument is an argument in if the 
premises (generally explicitly stated) are true, it would 
be impossible for the conclusion to be false. In order 
words, if the evidence is true, then the conclusion is 
necessarily true or the conclusion MUST BE TRUE. 
Deductive reasoning will be tested in verbal context 
(in the LSAT) and in the verbal and quantitative 
context in the other two graduate school tests – 
GMAT and GRE.  
 
An inductive argument is an argument in which the 
evidence used is such that the conclusion that is 
reached on the basis of the premises (explicit and 
implied) is merely PROBABLE, not CERTAIN.  All 
three tests – LSAT, GRE, and GMAT – will ask you to 
identify arguments in which the conclusion is merely 
one of several probable scenarios consistent with the 
evidence.  The Argument essays tested on all three 
tests are about your ability to identify OTHER equally 
probable conclusions that are consistent with the 
evidence.  GMAT and GRE will also test your ability to 
test more than ONE PROBABLE interpretation of the 
evidence and to see whether the conclusion that can 
reached on this basis is consistent across different 
scenarios consistent with the evidence.  
 
Because deductive arguments (also referred to as 
Logical Conclusions on the three tests) are those in 
which the truth of the conclusion is thought to be 
completely guaranteed and not just made 
probable by the truth of the premises (usually explicit 
or necessarily implied in the explicit information). In 
such arguments, the truth of the conclusion is 
"contained within" the truth of the premises; i.e., 
the conclusion does not go beyond what the truth of 
the premises implicitly requires. For this reason, 
© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 3 
deductive arguments are usually limited to inferences 
that follow from literal interpretation of the evidence 
and from universal definitions relied upon in  
mathematics and other rules of formal logic.  
 
For example, the following are deductive arguments 
in which the conclusion is necessarily true if the 
premises used as evidence are true:  
 
There are 120 people in the class, taking either 
English or Spanish language courses, and no person 
takes both courses. 80 people take English language 
courses. Therefore, there are 40 students taking 
Spanish language courses.   
 
Each year, the official estimate of the available cod in 
the Atlantic is made on the basis of an AVERAGE of 
the two estimates:  the official tonnage of cods caught 
by research vessels and the commercial tonnage of 
cods caught by other fishing vessels.  In the past, the 
two tonnages agreed were within 1% of each other. 
However, in the past, the official tonnage went 
markedly down by the same amount as the 
commercial tonnage went up.  Therefore, the official 
estimate remained practically unaffected.  
 
Notice that because the average is computed by 
adding up the two estimates and dividing the sum by 
2, if one of the values goes up by about the SAME 
amount as the other went down, then the sum of the 
two tonnages should remain the same and the 
average will remain unaffected.  The conclusion 
stated is a valid DEDUCTION and necessarily true. 
 
Inductive arguments or ILLOGICAL ARGUMENTS, 
on the other hand, can appeal to any consideration 
that might be thought relevant to the probability 
of the truth of the conclusion. Inductive arguments, 
therefore, can take very wide ranging forms, including 
arguments dealing with statistical data, 
generalizations from past experience, appeals to 
signs, evidence or authority, and causal relationships.  
© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 4 
To sum up, an INDUCTIVE ARGUMENT is one in 
which the conclusion that is drawn on the basis of a 
set of premises explicitly stated or implied in the line 
of reasoning is PROBABLE but NOT logically certain. 
The conclusion is but ONE of several PROBABLE 
interpretations of the evidence.   
 
X is an integer. Therefore, X is equal to 2. 
 
The above is an example of an INDUCTIVE argument 
in which the conclusion that X is equal to 2 is 
PROBABLE but not certain because X could also be 
1, 3, 4, 5 or any other positive or negative value or 
zero.  
 
A DEDUCTIVE ARGUMENT is one in which the 
conclusion is NECESSARILY CERTAIN if the 
evidence is true.  If X is an integer, then it is 
necessarily true that X is a whole number.  If John 
Scored 160 on the LSAT, then it is necessarily true 
that John took the LSAT because unless the test is 
taken, a score may not be obtained. 
 
All three tests will require that you logically interpret 
evidence or any statement and draw ‘deductions’ or 
necessarily valid conclusions. The Reading 
Comprehension section on the three tests will test 
your ability to make logical and literal interpretation of 
context-specific information relevant to the question.  
The Logical Reasoning Section on the LSAT and the 
Critical Reasoning Section on the GMAT and GRE 
will require that you draw conclusions that are 
logically certain for a set of stated or implied 
premises. 
 
Remember that questions asking you to identify that which 
‘could be’ true are about identifying probable answers 
consistent with the evidence.  IF the evidence is that ‘at most 
one person recognizes everybody in the room’ it is probable 
that one person recognizes everybody in the room. It is equally 
probably that nobody recognizes anybody in the room because 
‘at most’ implies equal to or less than. The questions asking you 
to identify that which MUST BE true for a set of premises asks 
you to pick an answer that is LOGICALLY CERTAIN for a set of 
evidence used. 
Page 5


© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 1 
CRITICAL REASONING 101 
 
wo guys are looking at a glass filled to half its capacity. One guy 
reaches the conclusion that the “glass is half full” and the other guy 
reaches the conclusion that the “glass is half empty”.  This story, in a 
nutshell, encapsulates what an ‘interpretation of evidence’ is all about.  In 
this instance, notice that the two so-called different interpretations have 
the SAME significance and the interpretations will qualify as ‘logical 
interpretations’.  On the other hand, if the person looking at the glass  filled 
to half its capacity were to reach the conclusion that ‘someone forgot to fill 
the entire glass’ or that ‘someone did not finish drinking all the liquid in the 
glass’, the person will be ‘guilty’ of making an ILLOGICAL CONCLUSION. 
 
An ILLOGICAL CONCLUSION is one that is derived on the basis of the 
stated EVIDENCE and on the basis of additional information TAKEN FOR 
GRANTED. The additional information taken for granted is the 
ASSUMPTION of the argument. In the first case, the persons reaching the 
conclusion that ‘the glass is half full or half empty’ did not bring in 
additional information into the argument in order to reach a conclusion. 
Therefore, the persons reaching the conclusion were ‘logical’ in their 
interpretation of the evidence. However, in the second case, the person 
looking at the same evidence ‘assumed’ or ‘took for granted’ that the ‘liquid 
in the glass could not have evaporated or spilled out, or could not have 
been drunk by the drinking bird’. (Therefore, the person forgot to fill it to 
the brim or forgot to drink all of it.) 
 
An ARGUMENT is essentially the conclusion of a line of reasoning using an evidentiary 
basis and additional information either taken for granted or not considered at all.  The 
EVIDENCE provides the CONTEXT for the Conclusion, and is critical to the conclusion.  
The conclusion of an argument taken alone is without context and may not shed light on 
the WHY of the conclusion. 
 
All information needs to be processed in terms of two questions:  WHAT is being said? 
And Why is it being said?  The conclusion answers ‘WHAT’ is being said whereas the 
evidence answers “WHY” the conclusion is being said. If the conclusion is that the ‘use of 
marijuana can cause cancer’, the basis or the context for this conclusion is that ‘an 
ingredient called THC inactivates the herpes virus that can trigger the uncontrolled growth 
of cancer cells’, we need to process both the WHAT and WHY of the argument.  
 
The test is about your ability to process information in context and to understand the 
question that relates to the argument in order that you pick an answer choice that is 
relevant to the specific scope of information that is presented to you and to the question 
posed to you. 
 
Do not process information in vague generalities. For example, the above argument about 
marijuana cannot be processed as ‘something about marijuana being bad’.  Process the 
specifics and deal with the question on that basis. 
 
 
T
© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 2 
 
LOGICAL REASONING 101 
 
Deductive and Inductive Arguments 
 
Logical Reasoning involves two types are arguments: Deductive 
and Inductive. 
 
A deductive argument is an argument in if the 
premises (generally explicitly stated) are true, it would 
be impossible for the conclusion to be false. In order 
words, if the evidence is true, then the conclusion is 
necessarily true or the conclusion MUST BE TRUE. 
Deductive reasoning will be tested in verbal context 
(in the LSAT) and in the verbal and quantitative 
context in the other two graduate school tests – 
GMAT and GRE.  
 
An inductive argument is an argument in which the 
evidence used is such that the conclusion that is 
reached on the basis of the premises (explicit and 
implied) is merely PROBABLE, not CERTAIN.  All 
three tests – LSAT, GRE, and GMAT – will ask you to 
identify arguments in which the conclusion is merely 
one of several probable scenarios consistent with the 
evidence.  The Argument essays tested on all three 
tests are about your ability to identify OTHER equally 
probable conclusions that are consistent with the 
evidence.  GMAT and GRE will also test your ability to 
test more than ONE PROBABLE interpretation of the 
evidence and to see whether the conclusion that can 
reached on this basis is consistent across different 
scenarios consistent with the evidence.  
 
Because deductive arguments (also referred to as 
Logical Conclusions on the three tests) are those in 
which the truth of the conclusion is thought to be 
completely guaranteed and not just made 
probable by the truth of the premises (usually explicit 
or necessarily implied in the explicit information). In 
such arguments, the truth of the conclusion is 
"contained within" the truth of the premises; i.e., 
the conclusion does not go beyond what the truth of 
the premises implicitly requires. For this reason, 
© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 3 
deductive arguments are usually limited to inferences 
that follow from literal interpretation of the evidence 
and from universal definitions relied upon in  
mathematics and other rules of formal logic.  
 
For example, the following are deductive arguments 
in which the conclusion is necessarily true if the 
premises used as evidence are true:  
 
There are 120 people in the class, taking either 
English or Spanish language courses, and no person 
takes both courses. 80 people take English language 
courses. Therefore, there are 40 students taking 
Spanish language courses.   
 
Each year, the official estimate of the available cod in 
the Atlantic is made on the basis of an AVERAGE of 
the two estimates:  the official tonnage of cods caught 
by research vessels and the commercial tonnage of 
cods caught by other fishing vessels.  In the past, the 
two tonnages agreed were within 1% of each other. 
However, in the past, the official tonnage went 
markedly down by the same amount as the 
commercial tonnage went up.  Therefore, the official 
estimate remained practically unaffected.  
 
Notice that because the average is computed by 
adding up the two estimates and dividing the sum by 
2, if one of the values goes up by about the SAME 
amount as the other went down, then the sum of the 
two tonnages should remain the same and the 
average will remain unaffected.  The conclusion 
stated is a valid DEDUCTION and necessarily true. 
 
Inductive arguments or ILLOGICAL ARGUMENTS, 
on the other hand, can appeal to any consideration 
that might be thought relevant to the probability 
of the truth of the conclusion. Inductive arguments, 
therefore, can take very wide ranging forms, including 
arguments dealing with statistical data, 
generalizations from past experience, appeals to 
signs, evidence or authority, and causal relationships.  
© Maple Leaf International Consulting, Inc., New York New York. 
For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 4 
To sum up, an INDUCTIVE ARGUMENT is one in 
which the conclusion that is drawn on the basis of a 
set of premises explicitly stated or implied in the line 
of reasoning is PROBABLE but NOT logically certain. 
The conclusion is but ONE of several PROBABLE 
interpretations of the evidence.   
 
X is an integer. Therefore, X is equal to 2. 
 
The above is an example of an INDUCTIVE argument 
in which the conclusion that X is equal to 2 is 
PROBABLE but not certain because X could also be 
1, 3, 4, 5 or any other positive or negative value or 
zero.  
 
A DEDUCTIVE ARGUMENT is one in which the 
conclusion is NECESSARILY CERTAIN if the 
evidence is true.  If X is an integer, then it is 
necessarily true that X is a whole number.  If John 
Scored 160 on the LSAT, then it is necessarily true 
that John took the LSAT because unless the test is 
taken, a score may not be obtained. 
 
All three tests will require that you logically interpret 
evidence or any statement and draw ‘deductions’ or 
necessarily valid conclusions. The Reading 
Comprehension section on the three tests will test 
your ability to make logical and literal interpretation of 
context-specific information relevant to the question.  
The Logical Reasoning Section on the LSAT and the 
Critical Reasoning Section on the GMAT and GRE 
will require that you draw conclusions that are 
logically certain for a set of stated or implied 
premises. 
 
Remember that questions asking you to identify that which 
‘could be’ true are about identifying probable answers 
consistent with the evidence.  IF the evidence is that ‘at most 
one person recognizes everybody in the room’ it is probable 
that one person recognizes everybody in the room. It is equally 
probably that nobody recognizes anybody in the room because 
‘at most’ implies equal to or less than. The questions asking you 
to identify that which MUST BE true for a set of premises asks 
you to pick an answer that is LOGICALLY CERTAIN for a set of 
evidence used. 
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For exclusive use by our registered participants only. Not to be copied or reproduced without our consent. 
Page 5 
HOW IS LOGICAL REASONING TESTED ON THE GRADUATE SCHOOL 
ADMISSION TESTS? 
 
LSAT LOGICAL REASONING SECTION 
 
LSAT test will include TWO scored sections of Logical Reasoning section, each 
section having 25-26 questions to be answered in 35 minutes.  WE will discuss 
the different types of questions that will be tested in this section on the LSAT. It is 
also probable that the test will include a third LR section that may not be scored, 
although it is more probable that the not-scored section will be Analytical 
Reasoning or Reading Comprehension. 
 
LSAT will measure your logical reasoning skills throughout the entire test and in 
the various sections.  While the Logical Reasoning Section is specifically geared 
to measuring your ability to critique inductive or illogical arguments, to engage in 
deductive reasoning using the evidence presented, and to identify parallel forms 
and logical explanations for the described paradoxes, the Reading 
Comprehension and Analytical Reasoning sections will also measure your 
inductive and deductive reasoning skills.  Reading Comprehension is about your 
ability to deductively interpret context-specific information relevant to the question 
and to identify the main point of the whole passage.  The Analytical Reasoning 
Section on the LSAT will ask you to draw logically certain conclusions using a set 
of statements provided to you and then to use the deductions to make further 
decisions about the presented questions. 
 
For example, if the ‘game’ in the Analytical Reasoning Section stated the 
following: 
A Storm passes through five towns and drops either rain or both rain and hail.  It 
passes through each town exactly once.  The storm passes through Oakville 
immediately AFTER it passes through Rockville. 
 
We would logically interpret the last statement to mean that Oakville cannot be 
the first town that the storm passes through and Rockville cannot be the last town 
that the storm passes through. We would then use this logically derived 
conclusion to check out valid and permissible scenarios for the storm’s path. 
 
If the ‘game’ stated that the five music stores in Ghost Town carried three genres 
of music:  Rock, Pop, and Jazz.  Each store must carry at least one genre of 
music.  Store B carries more types of music than Store C does and Store D 
carries more types of music than Store B does, we would ‘logically conclude’ that 
Store B must carry two types of music and Store D all three types of music.  
Store C must carry exactly one type of music in order to make the specified 
statements work and to be consistent with the requirement that each store carry 
at least one genre of music  We would then use this deduction to make further 
decisions about the scenarios presented. 
 
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