The author contends that the Objectivist epistemology has lacked a viable model of propositional knowledge for nearly fifty years, due to neglect of Rand's unit-perspective view of concepts. This pioneering insight, he says, not only is an essential building block of her concept theory, but also welds together the three levels of logical theory and provides the clearest X-ray picture of our multilayered conceptual knowledge. Using the unit-perspective to expand Rand's theory of concepts, the author then devises a theory of the proposition, giving considerable attention to axioms and statements about nonexistent subjects.

Introduction to Logic.

What's in Your File Folder?: Rand's Unit-Perspective, the Law of Identity, and the Fundamental Nature of the Proposition

a recent paper, Fabio Perin Shecaira (2013) proposes a defence of Waller’s deductivist schema for moral analogical argumentation. This defence has several flaws, the most important of them being that many good analogical arguments would be deemed bad or deficient. Additionally, Shecaira misrepresents my alternative account as something in between deductivism and non-deductivism. This paper is both an attempt at solving this misunderstanding and an analysis and criticism of Waller and Shecaira’s forms of deductivism.

https://ojs.uwindsor.ca/ojs/leddy/index.php/informal_logic/article/download/4112/3317

Deduction without Dogmas:The Case of Moral Analogical Argumentation

Lincoln persistently and effectively uses a number of "dialectical" or "dialogical" figures such as prolepsis, prosopopoeia , and correctio . These figures help to frame his rhetorical texts within a universe of argument and give him the opportunity to voice and transcend positions that differ from his own. Attention to this aspect of Lincoln's rhetoric helps to explain the power of his speeches and also offers a ground for connecting rhetorical practice with contemporary scholarship in informal logic, where there is an especially keen interest in the dialectical positioning of arguments.

Dialogic Figures and Dialectical Argument in Lincoln's Rhetoric

As the title suggests, the primary concern of this study is with problems arising from a very widely used notion in the recent literature of linguistics and philosophy, the notion of implicature. As this concept was introduced and developed by the philosopher H. P. Grice, the main part of the study will understandably be centred around his work. Grice distinguished between two main types of implicature, the conventional and the conversational. 
In the first part we will be concerned with, what Grice called, conventional implicature, and in particular with the linguistic items generating it, as described in his work. Thus the aim of this part of the study will be to investigate the nature of conventional implicata, and to ask whether they can be justifiably claimed to be nonconsequential for truth-evaluation and invariable, as Grice argues. Grice's account in this respect will be found to be partly implausible, as regards his treatment of 'therefore', and partly inadequate, as it fails to take into account the wide ranging function of 'but' - his paradigm of conventional implicature - but treats its variable meaning aspects as invariable, conventional implicature. In view of the intriguing linguistic behaviour of 'but', the main contributions to this topic in the literature will be reviewed. 
In the second part of the study our primary aim will be to consider in detail linguistic phenomena that come under the rubric of conversational implicature in the literature - with an emphasis on Grice's examples - with a view to detecting common characteristics that can be taken as the parameters along which these phenomena can be defined as a homogeneous class. It will be concluded that they cannot. More stringent criteria will be proposed for membership in a narrowly defined class of conversational implicature. Two classes of background knowledge and assumptions will be described and shown to bear significantly on language production and understanding and, in particular, on the production and understanding of linguistic facts that have been called conversational implicatures. It will be concluded that the term 'conversational implicature' has been misused and abused. The view taken here will be that background knowledge schemes must be taken into account and represented in a language theory, though the difficulties facing such an enterprise are well understood and acknowledged. 
However, the overall conclusion will be that Grice's proposal effects a cut and dried demarcation between a neat but narrowly defined truth-functional semantics, on the one hand, and an unexplicated pragmatics, on the other, that would, however, include the most intriguing aspects of language use. , This view of language is not very revealing and, hence, uninteresting and unappealing.

/pdf/problems-connected-with-the-notion-of-implicature-28u5urxi88.pdf

Problems connected with the notion of implicature

The author discusses how Rand’s largely underdeveloped concept of the “dual-aspect objective,” first introduced in the 1960s, is vital for understanding how knowledge is grounded in reality. He defines it, then applies it to perception and introspection, and to concepts, propositions, and syllogisms. The author also defines content of awareness, carefully distinguishing it from both object and form of awareness, and applies those distinctions throughout. In addition, he discusses how truth is both dual-aspect and contextual, and he extends his discussion in Part 1 of Rand’s “unit-perspective,” showing how units, too, have a dual-aspect, even on the level of syllogisms.

Introduction to Logic.

Citations

What's in Your File Folder?: Rand's Unit-Perspective, the Law of Identity, and the Fundamental Nature of the Proposition

Deduction without Dogmas:The Case of Moral Analogical Argumentation

Dialogic Figures and Dialectical Argument in Lincoln's Rhetoric

Problems connected with the notion of implicature

What's in Your File Folder? Part 2: Epistemology, Logic, and "The Objective"