Grue Paradox Analysis

932 Words2 Pages

The “grue paradox” presented by Nelson Goodman raises challenges for induction and makes us wonder why we make judgments and favor one hypothesis more than another. The “green” hypothesis is more compelling than the “grue” one in that “grue” is subject to changes in many circumstances.
The hypothesis that is discussed by Nelson Goodman is an enumerative induction, which concludes that “all emeralds are green” since all the many emeralds we have observed prior to 2020 are green. Instinctively, this type of inductive argument looks like a good argument due to the fact that the premises are certain examples with the same properties of the conclusion. This hypothesis is confirmed by observations of green emeralds because based on our knowledge so far, all emeralds are green and no exception has shown up. In this case, the generalization of all emeralds being green is confirmed by its examples, which are green emeralds.
However, by introducing a new term “grue”, Goodman says that not all generalizations are necessarily confirmed by their examples. Goodman defines “grue” as follows: “An object is grue if and only if it was first observed before 2020 A.D. and is green, or if it was not first observed before 2020 A.D. and is blue”. As we are in the year of 2014 now, all the evidence we have supports the “grue” hypothesis exactly as much as it supports the “green” hypothesis. Taking the inductive reasoning above, if we can conclude that “all emeralds are green”, it is equally true that we can conclude “all emeralds are grue”. Nevertheless, this will lead to an absurd conclusion that the emeralds we have observed so far are both green and grue, which obviously does not reflect the real case in science because the hypothesis th...

... middle of paper ...

...re events will occur as it always has in the past. For instance, the induction that “all swans we have seen are white and therefore all swans are white” is not justified because black swans were later discovered by Europeans in 1697. If someone has already observed 1000 emeralds that are green, normally what he will do is stop finding more emeralds and just make the conclusion that “all emeralds are green”. It might be true for a limited number of emeralds, but the generalization based on previous observations does not give us a guarantee because we have not examined all emeralds in the world.
Even with the problem of induction, we are still justified to conclude that all emeralds are green. Either out of common sense, or due to certain constraints the “grue” hypothesis has, we find the induction that concludes that all emeralds are green more compelling.

Open Document