Download INDUCTION

INDUCTION
ANALYTIC DEF’N
GENUS:
DIFFERENTIA:
General
principle
which states that
events in nature
are REGULAR, not
RANDOM
// The past, while not a carbon
copy of the future,
nevertheless resembles it. //
ANALYTIC DEF’N
DENOTATA:
The sun will rise in the
East tomorrow.
Flipping that switch will turn the
lights off.
DEF’N by
MILL & HUME
John Stuart Mill:
- assumption that there are such
things in nature that are
parallel
- under a sufficient degree of
similarity, these events happen
as often as the same
circumstances recur
"This universal fact, which is our
John Stuart Mill:
Example:
“The next piece of snow that I
will examine will be cold.”
David Hume
- the foundation of induction
(according to Mill) is that the
future will resemble the past
- any suspicion that the course of
nature may change = experiences
are useless = no
inference/conclusion
“It is impossible, therefore, that
any argument from experience can
prove this resemblance of the
David Hume
Example:
“The next piece of snow that I
will examine will be cold. “
All beliefs about unobserved
matters of fact are derived from
experience by induction.
Other Philosophers
- No need to justify the principle
because it works.
- To justify the principle by
saying that it works is
tantamount to using the principle
to justify itself.
NATURE of INDUCTION
• Fountainhead of all empirical
arguments
• Connects one particular event
with another, preventing
isolation of events
• PREMISES: observed
CONCLUSION: unobserved
NATURE of INDUCTION
•
Using as evidence what you
observed to be true in some
instances to a conclusion that the
same observation will obtain in
most cases, yet unobserved
(induction to justify your
conclusion)
• What is claimed in the conclusion
GOES BEYOND the evidence found in
the premises.
• The conclusion is made probable on
the basis of the truth of the
INDUCTION vs.
DEDUCTION
INDUCTION vs. DEDUCTION
* Specific to
General
* Uses
observations
* Conclusion is
regarded as a
hypothesis
(premises
support
the conclusion
* General to
Specific
* Uses general
truths/facts
* Used to test
or confirm a
hypothesis
* Reason/Logicbased
- false premise
INDUCTION vs. DEDUCTION
* Strengthen
your argument
or hypothesis
by adding
another piece
of information
* Adding more
evidence will
not/cannot
improve your
argument
INDUCTION vs. DEDUCTION
Example
Example
Socrates was
Greek.
Most Greeks eat
fish.
Therefore,
Socrates ate
fish.
All men are
mortal.
Socrates was a
man.
Therefore,
Socrates was
mortal.
INDUCTION vs. DEDUCTION
Example
Example
2 is divisible by
2.
2 is an even
number.
Therefore, all
even numbers are
divisible by 2.
All even numbers
are divisible by
2.
2 is divisible by
2.
Therefore, 2 is an
even number.
INDUCTION
Inductive arguments can
include:
-> PART-TO-WHOLE: where the
whole is assumed to be like
individual parts (only bigger).
-> EXTRAPOLATIONS: where areas
beyond the area of study are
assumed to be like the studied
area (same logic)
-> PREDICTIONS: where the future
Part-to-Whole
All chocolates I’ve tasted are
sweet.
Most chocolates are sweet.
Extrapolations
A ball is observed to move one
meter in one second.
//The ball will move 10 meters
in 10 seconds.
Predictions
The Azkals have won in all of
their previous matches.
Therefore, the Azklas will win
in their next game.
MORE EXAMPLES
"Every time you eat shrimp, you get
cramps. Therefore you get cramps
because you eat shrimp."
"Mikhail hails from Russia and
Russians are tall, therefore Mikhail
is tall."
"When chimpanzees are exposed to rage,
they tend to become violent. Humans
are similar to chimpanzees, and
therefore they tend to get violent
when exposed to rage."
RELIABILITY OF INDUCTIVE
INFERENCE
Marble experiment:
*100 marbles ; same SIZE, WEIGHT
& BRIGHTNESS;
-> but unsure of the COLORS
*Random selection of marbles
RELIABILITY OF INDUCTIVE
INFERENCE
GET 1 MARBLE.
RELIABILITY OF INDUCTIVE
INFERENCE
GET ANOTHER 9.
RELIABILITY OF INDUCTIVE
INFERENCE
GET ANOTHER 41.
RELIABILITY OF INDUCTIVE
INFERENCE
GET ANOTHER 48.
RELIABILITY OF INDUCTIVE
INFERENCE
When you have complete evidence to
confirm your generalization, you
have NOT made an inductive
inference.
REMEMBER: known to the unknown;
observed to the unobserved
Sources
http://www.iep.utm.edu/ded-ind/
http://philosophy.lander.edu/logic/ded_ind.h
tml
http://www.buzzle.com/articles/inductivereasoning-examples.html
http://changingminds.org/disciplines/argumen
t/types_reasoning/induction.htm
http://www.criticalthinking.com/company/arti
cles/inductive-deductive-reasoning.jsp
http://www.princeton.edu/~grosen/puc/phi203/
induction.html
http://plato.stanford.edu/entries/mill/#Ind
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