The more important and comprehensive the role played by the syllogistic form in rigorous inference, the more sensitive does pure thought become to any criticism that attacks the actual import and usefulness of this kind of inference. This, perhaps, is what motivates the efforts, referred to just above, of those who do not wish to see the exact inferences in the sciences come under the jurisdiction of the syllogism. For it is a well-known fact that philosophy long ago passed a very harsh judgment on the value of syllogistic inference for human knowledge.