The “Grue Paradox” presented by Nelson Goodman raises challenges to induction and leads us to question why we make judgments and favor one hypothesis over another . The “green” hypothesis is more compelling than the “crane” hypothesis in that the “crane” is subject to change in many circumstances. The hypothesis discussed by Nelson Goodman is an enumerative induction, which concludes that "all emeralds are green" since all of the many emeralds we observed before 2020 are green. Instinctively, this type of inductive argument looks like a good argument because the premises are some examples with the same properties as the conclusion. This hypothesis is confirmed by the observations of green emeralds because, according to our knowledge so far, all emeralds are green and no exceptions have appeared. In this case, the generalization that all emeralds are green is confirmed by its examples, which are green emeralds. However, by introducing a new term "crane", Goodman says that not all generalizations are necessarily borne out by their examples. Goodman defines "crane" as follows: "An object is crane if and only if it was first observed before 2020 AD and is green, or if it was not first observed before 2020 AD and is blue. As we are now in 2014, all the evidence we have supports the “Crane” hypothesis exactly as much as it supports the “green” hypothesis. Returning to the inductive reasoning above, if we can conclude that “all emeralds are green”, it is also true that we can conclude “all emeralds are crane”. Nevertheless, this will lead to an absurd conclusion that the emeralds we have observed so far are both green and crane, which obviously does not reflect the real case in science because the hypothesis...... middle paper.... ..new events will occur as has always been the case in the past. For example, the induction that "all the 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 anyone has already observed 1000 green emeralds, normally what he will do What we need to do is stop finding more emeralds and just conclude that "all emeralds are green". This might be true for a limited number of emeralds, but generalizing based on previous observations does not give us a guarantee because we have not examined all emeralds in the world. Even with the induction problem, we are still justified in concluding that all emeralds are green. Either by common sense or due to some constraints of the "crane" hypothesis, we find the induction which concludes that all emeralds are green more convincing..