Despite its basically syllogistic character, Richard Whately's Elements of logic presents the subject in a modern theoretical setting. Whately, for instance, regarded logic as an abstract science, and defined the syllogism as a purely formal device to be used as a means of determining the validity of all arguments. In this paper, I argue that such instances of abstractive ascent place Whately's theory in closer proximity to later 19th-century developments than to the work of his 17th-century predecessors. In addition to (...) discussing the theory itself, other sections deal with its historical setting, and various reactions to it. (shrink)

One way to determine the quality and pace of change in a science as it undergoes a major transition is to follow some feature of it which remains relatively stable throughout the process. Following the chosen item as it goes through reinterpretation permits conclusions to be drawn about the nature and scope of the broader change in question. In what follows, this device is applied to the change which took place in logic in the mid-nineteenth century. The feature chosen as (...) the focal point is the categorical syllogism. (shrink)

Logic is usually thought to concern itself only with features that sentences and arguments possess in virtue of their logical structures or forms. The logical form of a sentence or argument is determined by its syntactic or semantic structure and by the placement of certain expressions called “logical constants.”[1] Thus, for example, the sentences Every boy loves some girl. and Some boy loves every girl. are thought to differ in logical form, even though they share a common syntactic and semantic (...) structure, because they differ in the placement of the logical constants “every” and “some”. By contrast, the sentences Every girl loves some boy. and Every boy loves some girl. are thought to have the same logical form, because “girl” and “boy” are not logical constants. Thus, in order to settle questions about logical form, and ultimately about which arguments are logically valid and which sentences logically true, we must distinguish the “logical constants” of a language from its nonlogical expressions. (shrink)

In this paper we study the inferential analysis of the use of fallacies as a source of absurd communication. Starting from a diachronic review of perpectives, criteria and classification of fallacies, we analyze the fallacious arguments used in absurd discourses which are meant to trigger humor as well as the dislocation of the communicative sense.

Charles S. Peirce frequently mentioned reading Richard Whately's Elements of Logic when he was 12 years old. Throughout his life, Peirce emphasized the importance of that experience. This valorization of Whately is puzzling at first. Early in his career Peirce rejected Whately's central logical doctrines. What valuable insight concerning logic was robust enough to survive these specific rejections? Peirce recommended a biographical approach to understanding his philosophy. This essay follows that suggestion by considering Peirce's reading of Whately in a larger (...) life context. Surprisingly many factors in Charles Peirce's personal and intellectual development were at play when he read Whately. His father, Benjamin Peirce, oversaw rigorous home schooling intended to train young Charley for a brilliant intellectual career. Laboratory experience with qualitative chemical analysis exposed the boy to the logic of scientific investigation, specifically to the hypothetico-deductive method of inquiry. However, tensions between father and son developed over Charles' wish to devote his life to studying the logic of science. The two also disagreed upon the value of formal science. Against this background we will review relevant logical doctrines of Whately's book, as well as his innovative formalizing practice of logical inquiry. Then we will see that it was Whately's lessons about formal science that were of such importance to Peirce. (shrink)

Most recent discussions of John Stuart Mill’s System of Logic (1843) neglect the fifth book concerned with logical fallacies. Mill not only follows the revival of interest in the traditional Aristotelian doctrine of fallacies in Richard Whately and Augustus De Morgan, but he also develops new categories and an original analysis which enhance the study of fallacies within the context of what he calls ‘the philosophy of error’. After an exploration of this approach, the essay relates the philosophy of error (...) to the discussion of truth and error in chapter two of On Liberty (1859) concerned with freedom of thought and discussion. Drawing on Socratic and Baconian perspectives, Mill defends both the traditional study of logic against Jevons, Boole, De Morgan, and others, as well as the study of fallacies as the key to maintaining truth and its dissemination in numerous fields, such as science, morality, politics, and religion. In Mill’s view the study of fallacies also liberates ordinary people to explore the truth and falsity of ideas and, as such, to participate in society and politics and develop themselves as progressive beings. (shrink)