logic
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These slides are helpful if you really want to know what actually LOGIC is in business world or prospective.TRANSCRIPT
Junaid Ashraf
Logic is a study the methods and principles used to distinguish correct from incorrect reasoning.
Logic is also called Art of Arts and Science of Sciences.
It is a science of reasoning.
In logic we examine arguments of many varieties, in many spheres… argument in science and religion, ethics and law, politics and medicine, commerce and sports, and argument
arise in every day life.
LOGIC
Whatever the subject or content of an argument, the logician is interested in its form and its quality.
Does the argument do what it purpose to do?
If asserting the premises of some argument to be true does warrant asserting the conclusion also be true. Than the
reasoning is correct. Otherwise it is incorrect.
Propositions are either true or false, and in this they differ from questions, commands, and exclamations.
Only propositions can be either asserted or denied: questions may be asked and commands given and exclamations uttered, but none of them can be affirmed or denied, or judged to be
either true or false.
PROPOSITIONS
The difference between sentence and proposition is brought out by remarking that a sentence is always a part of a
language, whereas propositions are not peculiar to any of the languages in which they may be expressed.
It is raining (english)
Barsaat ho rai he (hindi)
Il pleut (french)
SENTENCE AND PROPOSITIONS
Simple proposition….A proposition making only one assertion.
Compound propositions…A proposition containing two or more simple propositions.
Disjunctive or Alternative Propositions….A type of propositions; if true at least one of the component proposition
must be true.
Hypothetical or conditional propositions …it is false only when the antecedents is true and the consequent is false.
KINDS OF PROPOSITIONS
An argument is not the mere collection of propositions, but has a structure. In describing this structure the term premise
and conclusion are usually employed
The conclusion of an argument is that proposition which is affirmed on the basis of the other propositions of the
argument
And these other propositions which are affirmed as providing grounds or reasons for accepting the conclusion are the
premises of that argument.
It should be noted that premise and conclusion are relative terms.
ARGUMENT
Inference …A process of linking propositions by affirming one propositions on the basis of one or more other propositions.
No proposition by itself, in isolation, is either a premiss or a conclusion.
It is a conclusion only when it occurs in an argument in which it is a claimed to follow from propositions assumed in that
argument. Like ‘employer’ and ‘employee’.
An argument always involves at least two proposition--- a conclusion plus one or more premisses.
The conclusion of an argument need not be stated either at its end or at its beginning. It can be, and often is, sandwiched
in between different premisses offered in its support.
ThereforeHence
SoAccordingly
In consequenceConsequentlyProves thatAs a result
For this reasonThus
For these reasons
SinceBecause
ForAs
Follows fromAs shown by
In as much asAs indicated by
The reason is that
Conclusion indicator Premise indicator
RECOGNIZING ARGUMENT
It follows thatI conclude that
Which shows thatWhich means thatWhich entails thatWhich implies that
Which allows us to infer thatWhich points to the conclusion
thatWe may infer
For the reason that
May be inferred from
May be derived from
May be deduced from
In view of the fact that
Conclusion indicator Premises indicator
It should be remarked that not every thing said in the course of an argument is either premise or conclusion of that argument. A passage containing an argument may also
contain other material, which is sometimes irrelevant but often supplies important background information that
enables the reader to understand.
Some passages may contain two or more arguments, either in succession, or intertwined.
In every argument one or more premises and a conclusion are asserted. But not every assertion of several propositions
constitute an argument
“if object of art are expressive, they are a language”
Such proposition is called a “conditional”.
No premiss is asserted, no inference is made, no conclusion is made to be true.
RECOGNIZING ARGUMENT
“Because objects of art are expressive, they are a language”.
Here we do have an argument.
A conditional statement may look like an argument, but it is not an argument; and the two should not be confused.
“synonyms are good servants but bad masters; therefore select them with care. (here there fore is a command rather than a proposition, and since a command is neither true nor
false. Premisses and conclusion must be asserted in an argument.
‘Since Henery graduated from medical school his probable income is very high’.
Since Henery graduated from medical school there have been many changes in medical techniques.
(in the second, the word “since” has temporal rather than logical significance.
Deductive----only deductive argument involves the claim that its premisses provide conclusive grounds for the truth of its
conclusion.
In the case of deductive arguments the technical terms “valid” and “ invalid” are used in place of “ correct” and
“incorrect”
DEDUCTION AND INDUCTION
Inductive-----inductive argument involves the claim that its premisses can not give coclusive grounds for its conclusion,
but only that they provide some grounds for it.
Inductive argument can be evaluated as better or worse.
In deduction we infer particular from general truths; while in inductionwe infer general from particular ……’