Inductive Logic

Question 1

How do scientists use induction to come up with hypotheses?

Answer 1

• a descriptive question about the context of discovery
• there is no algorithm for coming up with hypotheses, creativity and adaptability/time/place specific details change the method

Question 2

Is it reasonable to use induction to come up with hypotheses?

Answer 2

• an evaluative question about the context of justification

- it is reasonable but only has so much scope, can only deliver results to a certain extent.

Question 3

Under what circumstances do we take a hypothesis to be inductively justified?

Answer 3

• a descriptive question about the context of justification
• sometimes called, the ‘descriptive problem of induction’
• ‘the hypo-deductivist account of inductive support’: hypothesis H is inductively supported by evidence E if and only if H deductively entails E.

Question 4

Is it reasonable to take hypotheses to be inductively justified?

Answer 4

• an evaluative question about the context of justification

- traditional problem of justifying induction: problem of induction where justification is circular.

Question 5

Paradox of the Ravens

Answer 5

Hempel points out that due to positive instance, contraposition and positive instance
Seeing something contrary to the conclusion also inductively supports it.
For example, the argument that all ravens are black, fred is a raven therefore fred is black
Seeing a non-black non-raven confirms/supports the argument due to positive instance
All ravens are black is equivalent to all non-black things are non-ravens due to contraposition
therefore x being a non-black, non-raven confirms/supports that all ravens are black.

Question 6

The Grue Paradox

Answer 6

Nelson Goodman,
thought experiment that an object can be described as ‘grue’ only if it is examined before noon on the 12th March 2020 or after noon on the 12th March 2020 and blue.
In this case, observing that ‘a is an emerald and a is grue’ does not confirm or support the statement ‘all emeralds are grue’, thus challenging positive instance.

Question 7

Response to grue paradox

Answer 7

Perhaps positive instance holds true for normal predicates/situations, in this case, is it possible to specify what needs the predicate must meet?
Perhaps positive instance only stands true for natural kinds/natural groupings of predicates.
For example, would stand true for the statement that something is ‘H2O’ but not true for something such as ‘in my pocket or fallen onto the street’