truth and validity

8/9/2019 Truth and Validity

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TRUTH AND VALADITY


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VALID ARGUMENT

Valid argument is an argument such that it

is impossile !or premises to e true and

the conclusion !alse means in "hich the

conclusion !ollo"s "hich strict necessit#!rom the conclusion e$g$

All tele%ision net"or&s are media companies$

N'( is a tele%ision net"or&$

There!ore N'( is a media compan#$
















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INVALID ARGUMENT

An in%alid argument is an argument such that itis possile !or premises to e true and

conclusion !alse$ In in%alid arguments the

conclusion does not !ollo" "ith strict necessit#

!rom premises) e%en though it claimed to e$g$

All an&s are !inancial institutions$

*ells +argo is a !inancial institution$There!ore

N'( is a media compan#$

There!ore) *ells +argo is a an&$


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,-UND ARGUMENT

A sound argument is a deductive

argument that is valid and has all true

premises. Both condition must be metfor an argument to be sound. A sound

argument, therefore, is what is meant

by a good deductive argument in the

fullest sense of the term.


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UN,-UND ARGUMENT

An unsound argument is a deductive

argument that is invalid has one or more

false premises, or both. For anargument to be unsound, the false

premise or premises must actually be

needed to support the conclusion.


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INDU(TIVE ARGUMENT

Inductive argument is the one in which

the premises are claimed to support the

conclusion in such a way that it isimprobable that the premises be true and

the conclusion false.


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,TR-NG ARGUMENT

It is an inductive argument such that it is

improbable that the premises be true and

the conclusion false. In such arguments,

the conclusion follows probably from the

premises e.g.


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All dinosaur bones discovered to this day

have been at least 5 million years old.

!herefore, probably the ne"t dinosaur

bone to be found will be at least 5 million

years old. In this argument the premise is

actually true, the conclusion is probablytrue. #o the argument is strong.


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*EA. ARGUMENT

It is an inductive argument such that the

conclusion does not follow probably from

the premises, even through it claimed to.

e.g.

$uring the past fifty years, inflation has

consistently reduced the value of %a&istanirupee. !herefore, industrial productivity

will probably increase in the years ahead.


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In this argument, the premises is actuallytrue and the conclusion is probably true in

the actual world, but the probability of theconclusion is no way based on theassumption that the premises is true.

Because there is no direct connectionbetween inflation and increased industrialproductivity, the premise is irrelevant to theconclusion and it provide no probabilistic

support for it. !he conclusion is probablytrue independently of the premise. As aresult the conclusion is wea&.


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(-GENT ARGUMENT

It is an inductive argument that is strong and has all truepremises. In other words a cogent argument is theinductive analogue of a sound deductive argument andis what is meant by a good inductive argument without'ualification. Because the conclusion of a cogent

argument is genuinely supported by true premises, itfollows that the conclusion of every cogent argument isprobably true. !here is a difference between sound andcogent argument. In a sound argument it is onlynecessary that the premises be true and nothing more.(hile in a cogent argument the premises must not onlybe true, they must also not ignore some important pieceof evidence that outweighs the given evidence andentail a 'uite different conclusion. e.g.


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#wimming in #ardaryab is usually lots of

fun. !oday the water is warm, the surf is

gentle and on this beech there are no

dangerous currents. !herefore, it would be

fun to go swimming here now.

If the premises reflect all the important

factors then the argument is cogent. But if

they ignore the fact then the argument is

not cogent. !hus, for cogency thepremises must not only be true but also

not over loo& some important factors.


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UN(-GENT ARGUMENT

An uncogent argument is an inductive

argument that is wea& has one or more

false premises or both.


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$IA)*A+ #-(I) /A*I-0#

A1!2*A!I/2# -%2 !-#!A!2+2!# A$ A*)0+2!


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INDEDU(TIVEARGUMENT

,TR-NG *EA.

(-GENT UN(-GENT


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,TATEMENT

True

+alse


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DEDU(TIVEARGUMENT

VALID INVALID

,-UND UN,-UND


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+ALLA(IE,


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+ALLA(Y

A fallacy is an argument which appears to be

valid but in reality it is not so. It is an invalid

argument which is camouflaged and which can

deceive or mislead us by a show of truth. It is,so to spea&, a trap, something !ric&y or hidden.

Being mista&es in reasoning, fallacies arisesfrom the violation of one or other of the

principles on which the correctness of

reasoning depends.


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A fallacy may be committed unintentionally or intentionally.

(hen the fallacy is committed unintentionally it is called

paralogism.

A$

when it is committed intentionally then it is called sophism.

Fallacies can be formal and informal.


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+-RMAL +ALLA(Y

A formal fallacy is one that can be

detected by analy3ing the form of an

argument, such fallacies affect only

deductive argument.


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IN+-RMAL +ALLA(Y

An informal fallacy is one that can be

identified only by analy3ing the content of

an argument, such fallacies can affect

both deductive and inductive arguments.


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+ALLA(IE, -+ RELEVAN(E


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THE +ALLA(Y -+ RELEVAN(E

!he fallacy of relevance share the common

characteristics that the argument in which they

occur have premises that are logically irrelevant

to the conclusion. 4et the premises are relevant

psychologically, so the conclusion may seem to

follow from the premises, even though it does not

follow logically.


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In an argument that commit fallacy of

relevance, the connection between

premises and conclusion is emotional. !o

identify a fallacy of relevance, one must be

able to distinguish genuine evidence from

various forms of emotional appeal.

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