Basic Logical Knowledge

2002 ◽  
Vol 51 ◽  
pp. 279-304 ◽  
Author(s):  
Bob Hale

At least some of us, at least some of the time—when not in the grip of radical sceptical doubt—are inclined to believe that we know, for example, that if we infer a conclusion from two true premises, one a conditional whose consequent is that conclusion and the other the antecedent of that conditional, then our conclusion must be true, or that we know similar things about other simple patterns of inference. If we do indeed have knowledge of this sort, it is what I mean by logical knowledge. Logical knowledge is, roughly speaking, knowledge about logic—such as knowledge that a certain principle of inference necessarily preserves truth, or that every proposition of a certain form must be true—and so is not the same thing as knowledge that is gained by using logic, i.e. inferential knowledge. That is not to say, of course, that logical knowledge can't be inferential. On the contrary, it is barely open to question that—if there is any logical knowledge at all—there is a lot of inferential logical knowledge. For example, if we know that the introduction and elimination principles for the conditional are truth-preserving, we can surely get to know, by inference, that the principle of hypothetical syllogism (i.e. transitivity of the conditional) is so too, not to mention other, less obvious and more recondite, examples of putative logical knowledge.

Tekstualia ◽  
2018 ◽  
Vol 1 (4) ◽  
pp. 125-144
Author(s):  
Miłosz Wojtyna

Summarising recent developments in postclassical narratology and imagology, the article traces affinities between the two disciplines in order to observe the challenges that await the researchers of image and narrative in what Baudrillard called the simulation culture. Two case studies presented in the article (one devoted to Instagram visual narratives, the other – to a YouTube advertising campaign) illustrate challenges for the study of eventfulness, narrativity, and fictionality, and suggest - in line with the postulates of Mark C. Taylor and Esa Saarinen – that a radical change of educational and communicative practices is needed in contemporary Western societies. A change of this sort, it is postulated, might be instigated by the collaboration of researchers in visual studies and narrative theory.


Author(s):  
Imran Saleem ◽  
Yasir Arafat

Fabrication is strictly prohibited in Islam .For The Holy Prophet (Peace be upon him) mentioned the Hell fire as penalty for those who fabricate .Molana Anwaar ullah Farooqi is renowned scholar for his distinguished research regarding fabrication .He differed his former scholar regarding presumptions to declare a narration as fabricated .He does not consider odd words of a narration only reason to declare it fabricated .Whereas ,he also considers the spiritual revelations  a source to authenticate a Hadith .Moreover ,he also differs his formers regarding exaggeratedly mentioned penalty or  reward   for some deed. In short, he just turned the other side of coin .In his research he just emphasized the possibilities that may sort it to Sahih hadith.


1992 ◽  
Vol 27 (1) ◽  
pp. 52-65 ◽  
Author(s):  
Mihaly Simai

DURING ONE OF MY RECENT TALKS ABOUT THE MAIN problems in Hungary to foreign businessmen in the autumn of 1991, I was asked by a Japanese banker to enumerate the five most important issues that unite and divide Hungarians. It sounded like a simple assignment, and yet when I started to answer I came to realize that it was, in fact, a very difficult one. This was not because I was unable to list even ten issues; indeed, my problem was of a different sort. It was easy to talk about issues that were dividing the population, like Hungary's policies with respect to the market system, to privatization, to compensation for former property owners, and so forth. On the other hand, however, those issues which ostensibly unite the great majority of Hungarians — like democratization, freedom, national integrity, and human rights — are not necessarily understood by all to mean the same thing. There are stark differences of opinion on these issues; however, I added that this seemed quite normal and that it has not resulted in any sharp or violent confrontation.


1880 ◽  
Vol 26 (113) ◽  
pp. 55
Author(s):  
M. Ernest Chambard

This case shows some features common to the foregoing one, and evidently belongs to the same class. It is that of a young woman, 23 years old, who showed no hysterical tendency till the age of 20, when she received a severe mental shock by being witness to an attack of suicidal mania on the part of her mother, who was removed to the St. Anne Asylum. From that time she became triste, and complained of epigastric sensations. The developed attacks did not occur till three years later. She was a well-developed, chlorotic girl, subject to attacks of vomiting and precordial pain; ordinarily placid, she was yet emotional, but not delirious or excitable. She constantly dwelt on her mother's madness, and the scene she had then witnessed played a large part in her somnambulic state. She had no anaesthesia or analgesia; no ovarian tenderness or neuralgia. The somnambulic state was of two forms—the one simple, quiet sleep; the other accompanied by various nervous disturbances and by talking. They occurred spontaneously, and could also be provoked by pressure on the ovarian region, by closing the eyelids, &c, and she described their onset as accompanied by a sensation ot some kind of a ball rising from the lower part of the abdomen to the throat and stifling her. Then she passed into deep sleep, in which she could be made to converse, to answer questions slowly, performing voluntary actions, but with diminished sensibility. The return to the normal state was as abrupt as the lapse from it, and either occurred spontaneously or by opening her eyes, blowing on the neck. After the attack she was quiet; complained of pain in the head and limbs, and appeared fatigued, retaining no recollection of what she had passed through or done whilst in the hypnotic condition; a loss of memory that held also for the events immediately preceding her entrance into that state. Sometimes she was much surprised on waking not to find the tonic which she had drunk during the attack, and sharply accused the bystanders of having robbed her of it. Sometimes she was astonished to find herself sitting in a chair at some distance from the bed. The other kind of seizure took the form of delirium, in which she would hold conversations with imaginary individuals, and enact scenes she had passed through previously. By simply suggesting topics to her when in this state, anyone could start a long attack of this sort. It seems that every vivid moral impression, or even intellectual fatigue would give rise to a somnambulistic attack. Once the admission of an insane patient into the ward affected her so much, apparently by calling up the recollection of her mother's attack, that a few hours afterwards, whilst seated with her companions trying to work, but unable to do so, she suddenly closed her eyes, fell into a lethargic state lasting a quarter of an hour. An attack could also be induced by wearying her with conversation and questionings, as well as by various mechanical and sensorial excitations, as pressure on the ovarian region, a bright light, the “magnetic forms” of Braid—magnetism itself. M. Chambard adds some interesting comments.


1957 ◽  
Vol 22 (3) ◽  
pp. 233-236
Author(s):  
Bernard K. Symonds ◽  
Roderick M. Chisholm

The inferences countenanced by the traditional rules of modus ponens, modus tollens, disjunctive syllogism, hypothetical syllogism, and the complex types of dilemma may be regarded as single applications of one rule of inference, “the rule of complementary elimination”. In the present paper, we shall discuss this rule informally and illustrate it in application to expressions written in the language of Principia Mathematica. Our illustrations will contain no connectives except for those for conjunction, disjunction, and negation; we use parentheses in place of dots; and we allow disjunction and conjunction to have any number of operands more than two.In applying complementary elimination to a set of premises, we take the following three steps, (i) We form, merely by disjoining the premises, an expression which we shall call a premise disjunction, (ii) If we have n premises, we eliminate n minus one (or fewer) pairs of the following sort from our premise disjunction: each pair is such that one of its members is the negation of the other and both members are specific occurrences of disjuncts of our premise disjunction. We shall call such pairs complementary pairs, (iii) The formula obtained by means of our second step is one that may be made well-formed merely by eliminating parentheses or connectives other than negation; we make such elimination, and any formula we thus obtain is a consequence of our premises.


2000 ◽  
Vol 50 (1) ◽  
pp. 247-251
Author(s):  
Susanne Bobzien

In chapter 6 of Alcinous’ Handbook of Platonism we find a discussion of categorical, hypothetical, and mixed syllogisms. Alcinous distinguishes three figures of the hypothetical syllogism, and illustrates each figure with a syllogism based on an argument from Plato. Here he remarks in passing that most people called the second hypothetical figure the third and that some called the third figure the second. We may assume that those who called the third figure the second and those who called the second the third were the same. In a parallel passage, Alexander of Aphrodisias advocates the same ordering of figures of hypothetical syllogisms as Alcinous, and reports that Theophrastus, in the first book of his Analytics, had the second and third figure in reverse order. Combining these passages, we can infer that at the turn of the second century A.D. there existed two different views on the ordering of the figures of the hypothetical syllogisms, of which one goes back to Theophrastus, whereas the other presumably was the result of a later change.


1988 ◽  
Vol 62 (03) ◽  
pp. 411-419 ◽  
Author(s):  
Colin W. Stearn

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species isStylostroma sinense(Dong) butLabechia palliseriStearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described areClathrostromacf.C. jukkenseYavorsky,Gerronostromasp. (a columnar species), andStromatoporasp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).


1967 ◽  
Vol 28 ◽  
pp. 207-244
Author(s):  
R. P. Kraft

(Ed. note:Encouraged by the success of the more informal approach in Christy's presentation, we tried an even more extreme experiment in this session, I-D. In essence, Kraft held the floor continuously all morning, and for the hour and a half afternoon session, serving as a combined Summary-Introductory speaker and a marathon-moderator of a running discussion on the line spectrum of cepheids. There was almost continuous interruption of his presentation; and most points raised from the floor were followed through in detail, no matter how digressive to the main presentation. This approach turned out to be much too extreme. It is wearing on the speaker, and the other members of the symposium feel more like an audience and less like participants in a dissective discussion. Because Kraft presented a compendious collection of empirical information, and, based on it, an exceedingly novel series of suggestions on the cepheid problem, these defects were probably aggravated by the first and alleviated by the second. I am much indebted to Kraft for working with me on a preliminary editing, to try to delete the side-excursions and to retain coherence about the main points. As usual, however, all responsibility for defects in final editing is wholly my own.)


1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.


1966 ◽  
Vol 24 ◽  
pp. 337
Author(s):  
W. Iwanowska

A new 24-inch/36-inch//3 Schmidt telescope, made by C. Zeiss, Jena, has been installed since 30 August 1962, at the N. Copernicus University Observatory in Toruń. It is equipped with two objective prisms, used separately, one of crown the other of flint glass, each of 5° refracting angle, giving dispersions of 560Å/mm and 250Å/ mm respectively.


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