New riddle of induction

The new riddle of induction (english new riddle of induction ), also Goodman 's paradox ( Nelson Goodman), is a problem in which it comes to the verification of two expressions that differ only in future predictions. Both statements are verified by the given observation data in the same way and are therefore equally likely.

Starting point

Goodman's starting point is the old riddle of induction ( Hume problem), namely the question of under what conditions an induction circuit is viewed as credible: How many times do we see a confirmed our suspicions that we derive from it a law?

A typical induction conclusion would be, for example: all " found so far " emeralds were green, that all emeralds are green ( all found in the future ).

Grue

Goodman now (also the main bleen yet, both art words that were formed from green and blue) invents a property called grue. Things with this property are green when they are found before any future time t0 and are later found blue.

Had the property grue emeralds and would t0, for example, January 1, 2014, then would create a paradox:

• All emeralds that are found prior to this date, are green. This justifies the induction conclusion: The emeralds are found after this date will also be green.

At the same time the following applies:

• All emeralds found before that date are grue. This justifies the induction conclusion: the emeralds that are found after this date will also be grue (ie then blue).

The paradox consists in the fact that we create with the help of data from our assumptions laws that but really of the same data contradictory assumptions are also confirmed, but so we think and act as if our established laws valid.

Hume wondered, from when we were ready to believe in a causal relationship. Flashes it in our neighborhood and we hear shortly after a thunder, so we take the only true the first time. In the second or third time we suspect a connection. In perhaps the hundredth time, where always a flash followed by a thunderclap, we see our suspicion confirmed and speak of a law. But there from which we see confirms our assumption no " nameable " time, and even thousands of sequences Flash → thunder without a close lightning once only followed no thunder, does not justify us to believe that there is always so would it could be the 1001. lightning, the thunder is not followed precisely.

Goodman adds here just something really obvious: if an ultimately we can not justify our inductive inferences, they are arbitrary in some way, so go other. In the broadest sense can still be challenged on the Occam's razor principle: as long as it is possible, should be based on the simplest. In a narrower sense, however, Goodman still uses a time variable, so that at least all future assumptions are affected.

Criticism

The Goodman 's paradox is frequently seen as a stumbling block to Karl Popper's methodology. Bartley, however, considered it as a trivial mystery as to the jumps in the theory of inductive support. The reason that a statement such as " All emeralds are grue " would not be taken seriously by scientists, have nothing to do with the existing empirical evidence. Rather, it will not be taken seriously because there is no problem in mineralogy, the answer that allegation. So it was not only the empirical falsifiability of a hypothesis, what it was all a justification -free methodology.