Essential Questions

How can new knowledge be acquired using inductive logic?

What is more certain, the conclusions drawn from deductive or
inductive reasoning?

What are some of the issues with depending on inductive
reasoning as a way of knowing?
Comparing Inductive vs.
Deductive Reasoning

Inductive reasoning starts from a
specific set of observations and leads
to a general conclusion.

Deductive reasoning starts from a
general statement/premise and leads
to a specific conclusion.
Thinking …

Since inductive reasoning moves from the observed to the
unobserved it enables us to make everyday generalizations
or inferences about things we observe.

For example: since my neighbors dog is always friendly to
me when I walk past it I am confident that it will not bite me
today.

Can you think of any everyday examples of inductive
reasoning you have used recently?
Use of Inductive Reasoning in
Marketing and Statistics

Statistics makes general statements about a general
population using data collected from a random sample.

Used in many fields: drug development, medical research,
insurance, economics, psychology, engineering,
environmental science, engineering. . .

Correlations are drawn between the observations made
and the possible factors that contribute to their occurrence
or cause.
Issues with
Inductive Reasoning:

We cannot totally rely on what we observe with our senses.

How many examples do you need to observe before a
general conclusion can be drawn?

Statistics that use inductive reasoning can be misused,
distorted, and misinterpreted especially if they make
generalizations beyond what the data allows.

Inductive reasoning produces only general statements so
you can never guarantee the truth of the conclusions made.

Generalizations …
What distinguishes a good generalization?
1.
You should look at a reasonable number of instances. If you
see one dog swimming, this is not enough to conclude that all
dogs can swim.
2.
You should look at a variety of circumstances. Look at a
variety of different breeds of dogs swimming.
3.
You should actively look for counter examples. Ask if
anyone has seen a dog that can’t swim.
4.
You should demand more evidence (coherence) to support
surprising claims.
5.
You should be aware of the subject area and keep in mind
that generalizations in the natural sciences are more reliable
than those in the social sciences.
Lateral Thinking – Creative Reasoning

Since we cannot not rely entirely on inductive
or deductive reasoning as a way of knowing
there are times we need to be able to think in a
way that does not involve traditional forms of
deductive and inductive logic.

We need to be able to think outside the box and
come up with more creative ways of drawing
conclusions. This is called lateral thinking.

Lateral thinking alerts us to things we assume
without realizing we have assumed them.
Activity:
Give a rational explanation to each of the following
situations. In each case you need to question your
assumptions and try and think outside the box.
1.
A man walks into a bar and asks the barman for a
glass of water. The barman pulls out a gun and
points it at the man. The man says thank you and
walks out.
2.
A women is lying dead in a field. Next to her is an
unopened package. There is no other creature in the
field. How did she die?
Comparing Deduction and
Induction
Deduction
Induction
Reasoning from general
Reasoning from specific
statements or premises to a observations to a general
specific conclusion
conclusion
Conclusions are more
Conclusions are less certain
certain
Gives us more information
Give us less information
about the world enabling us
about the world
to gain more new
knowledge
Uses sense perception to
Uses induction to produce
produce the specific
the general statements
observations
Bibliography

Theory of Knowledge Course Companion,
Dombrowski, Rotenberg and Bick, OUP

Theory of Knowledge for the IB Diploma, van
de Lagemaat, Cambridge

Theory of Knowledge, Alchin, Hodder Murray

http://www.edwarddebono.com/about.htm