"We frequently use hypotheticals in our arguments with the common sense assertion that they are a logical form. "If I pass my exams then I will be able to continue my studies. I passed my exams therefore I will be continuing my studies". The conclusion of such an argument is clearly inferred from the hypothetical. Yet hypotheticals are one of the long-standing problems in the study of logic: the claim that they fall under the logical form has never been proven. So how then can logic claim to be the science of formal inference? Peter Long resolves these difficulties and others, and challenges traditional thinking in the area. In addition to his essay on hypotheticals, this study also contains two essays concerned with classical problems in philosophical logic, relating to notions of logical form and formal relations. How do we relate a thing with having a property as in "This sheet is white" or of the proposition "London is north of Paris", where this is an expression of a relation to a relation?"--BOOK JACKET.