it is about logical inference and logical inquiry.

1. Logical inference and inquiry
Prepared BY : Dambar Singh Khatri
Mahenra Ratna Campus
M. ED. science( first semester)
ODL students
Roll no: 62
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2. What is logic
• Logic is the codification of language into a deductive
system.
• Logic has two main parts i.e. semantics (meaning of
symbol) and syntax ( the rule that those symbol follows).
• The purpose of the semantics is to codify words and
concepts in a language.
• The purpose of syntax is to show which arguments are
valid( the truth of the premise implies the truth of the
conclusion.
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3. Logical inference
• Inference is simply conclusion or assumption of
certain arguments.
• Arguments are collection of statements.
• Inference is used to create new sentence that logically
follow from a given set of predicate calculus
sentence.
• So there are set of premises from where conclusion
is derived.
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4. • The conclusion may be correct or incorrect, or
correct to within a certain degree of accuracy, or
correct in certain situations.
• Conclusions inferred from multiple observations may
be tested by additional observations.
• For eg, all dogs are animals. All animals have four
legs. Therefore dogs have four legs.
•
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5. Rule of inference
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6. • The validity of an inference depends on the form of the
inference.
• The word "valid" does not refer to the truth of the
premises or the conclusion, but rather to the form of the
inference.
• An inference can be valid even if the parts are false, and
can be invalid even if some parts are true.
• But a valid form with true premises will always have a true
conclusion.
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7. • For eg, a statements
• all dogs are animal.
• All animals have four legs.
• Therefor All dogs have four legs.
• Suppose ; dogs(p), animal(q) and four legs(r)
• By use of rules we derive an equation..
P q,
q r
჻ p r
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8. Logical inquiry
- An inquiry is any process that has the aim of augmenting
knowledge, resolving uncertainty or solving a problem.
- Inquiry is closely related with normative science of logic.
- Theory of inquiry was extracted by Peirce with the help of Kant.
- According to John Dewey, inquiry involves the transformation of a
“situation” rather than a point of view.
- Peirce examined three fundamental modes of reasoning that play a
role in inquiry, commonly known as abductive, deductive,
and inductive, inference.
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9. • Abductive : It is a form of logical inference which starts
with an observation or set of observations and then seeks
to find the simplest and most likely explanation for the
observations.
• Deductive : It is the process of reasoning from one or
more statements (premises) to reach a logically certain
conclusion.
• Inductive : It is a method of reasoning in which
the premises are viewed as supplying some evidence for the
truth of the conclusion.
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