avicenna has divided the conditionals to the real cogent (i.e. with possible antecedent) and the verbal cogent (i.e. with the impossible antecedent). denying the truth of the latter, he caused controversies among moslem logicians. at the paper, we report the controversies, analyze the real and verbal cogent conditionals, formalize them in modern modal and relevant logics, and finally, defend id...

By treating belief as a modality and combining this with problems about constant truth tel lers and constant l iars (knights and knaves) we obtain some curious epistemic counterparts of undecidability results in metamathematics. Godel's second theorem gets reflected in a logician who cannot believe in his own consistency without becoming inconsistent. Lob's theorem reflects i t se l f in a vari...

is also a term. The usual versions of FOL do not provide for complex function expressions. Logicians usually count beginning with 0; 0-place function expressions are allowed, and in fact these are the same as individual constants. Predicate expressions combine with terms to make formulas. Like function expressions, predicate expressions are typed according to the number of arguments that they t...

Introduction The "relevance" logicians of North America and the "relevant" logicians of the Antipodes have long claimed that their logical systems are in better agreement with common sense than is classical logic. The present paper is a critical examination of such claims. Though it is part of an on-going debate between classical and relevantistic logicians, I have tried to keep my discussion o...

some logicians as avicenna, khaja nasir al-din tusi, and dabiran katebi believe that denotation (dilala) is dependent on volition (irada), and as long as there is no volition, there is no denotation. some others like qutb al-din razi completely reject this idea and maintain that denotation merely depends on “knowledge of designation” (al-ilm bi al-wad’). some of methodologicians of jurisprudenc...

Logic is usually presented as a tool of rational inquiry; however, many logicians in fact treat logic so that it does not serve us, but rather governs us – beings we are subordinated to the logical laws aspire disclose. We denote view primarily serves logica serviens, while denoting thesis our reasoning dominans. argue treating dominans misguided, for leads idea “genuine” within language. Inste...