Öz
There are two methods that humans use when they reason and produce knowledge about things, namely, deduction and induction. Whereas the former makes something unknown be known by proceeding from general knowledge, the latter proceeds to new general knowledge from some particular things that are already known. Deduction, having this property, is argued to be a “solid” reasoning or inference. Induction, on the other hand, is believed not to be a “solid” form of inference because it tries to reach a prediction on the basis of some observations, but that prediction can easily be refuted by something that is not observed by itself. The basis of the critique directed to deduction is that the quality that explains the “solidness” of the former is that what is to be explained is already contained within the proposition that the inference rests on. In other words, deduction does not provide us with new knowledge. Induction on the other hand produces new knowledge through the general proposition that it expresses as a conclusion. Depending on which argument is adopted, the only legitimate method of science is asserted to be either induction or deduction. Nevertheless, in order for human beings to think, they must use both methods. There is no quality that makes one better over the other. Moreover, when the varieties of the being on which induction reasons is taken into account, it can be seen that induction about some objects is just as solid as the deduction itself.