Full-text resources of CEJSH and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl

Results found: 4

first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  Euclid
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
PL
Euclid's 'Elements' Book V develops theory of proportion of 'geometric magnitudes'. Definition V,5 is the definition of proportion, A:B::C:D, definition V,7 is the definition of the order of ratios, A:B - C:D. In commentaries on Book V it is usually supposed, and sometimes even proved, that the order of ratios is a total order, while it is also supposed that 'magnitudes of the same kind' obey the Archimedean axiom only, i.e. Euclid's definition V,4. The purpose of this paper is to show that the linearity of the order of ratios cannot be deduced from the Archimedean axiom; to this end we define a structure of magnitudes that obeys the Archimedean axiom and show that the conjunction of negations is satisfied (for mathematical symbols applied see the original paper).
2
85%
EN
Piero della Francesca is best known as a painter but he was also a mathematician. His treatise De prospectiva pingendi is a superb example of a union between the fne arts and mathemati‑ cal sciences of arithmetic and geometry. In this paper, I explain some reasons why his paint‑ ing is considered as a part of perspective and, therefore, can be identifed with a branch of geometry.
PL
We confront Plato's understanding of equality in geometry with that of Euclid. We comment on Phaedo, 74b-c, Meno, 81e-85d and Elements, Book I. We distinguish between two meanings of equality, congruence and equality of the area, and show that in Plato equality means congruence. In Euclid, starting with the first definitions until Proposition I.34, equality means congruence. In the proof of Proposition I.35 equality gains a new meaning and two figures that are not congruent, and in this sense unequal, are considered to be equal. While Plato's geometry is based on self-evident facts, Euclid's geometry rests on deduction and the axioms that are by no means self-evident. However, the shift of meaning from congruence to equality of the area can be substantiated by reference to Euclid's axioms of equality. Finally, we present an ontological interpretation of the two attitudes to equality that we find in Plato's and Euclid's writings.
PL
W naszym artykule skupiamy się na analizie struktury podwójnej negacji w poemacie Parmenidesa, ze szczególnym uwzględnieniem B 2. Punktem wyjścia analizy jest stoicka klasyfikacja negacji, którą przedstawia Diogenes Laertios (VII.69-70). Obejmuje ona: negację, przeczenie, prywację oraz podwójną negację. Przykład podany przez Diogenesa Laertiosa zapisujemy następująco: „Nie (nie jest dzień)” ↔ „jest dzień”. W warstwie poetyckiej, podwójna negacja spełnia funkcję wzmocnienia ekspresji wypowiedzi bogini. Z kolei w kontekście ontologii Parmenidesa, prawo podwójnej negacji służy afirmacji „jest”. Naszym celem jest szczegółowa analiza konstrukcji podwójnej negacji. W kolejnym kroku wprowadzamy dowody nie wprost z Elementów Euklidesa. Pokazujemy, że wszystkie cztery formy negacji, które wymienia Diogenes Laertios, występują w Elementach i że zawierają one bogatszy zestaw form językowych służący wyrażeniu negacji, w tym podwójnej negacji. Pokazujemy wreszcie, że Parmenides świadomie stosuje prawo podwójnej negacji, a poemat jest pierwszym w historii tekstem filozoficznym poświadczającym użycie tego prawa. Podwójna negacja może być wyrażona krótko jako: u stoików (Diogenes Laertios VII.69-70): „nie (nie jest dzień) ↔ jest dzień”; u Euklidesa: „Nie (jest nie-równe) ↔ Jest równe” (Elementy, I.6); „Nie jest tak, że (…. nie jest wokół…) ↔ Jest wokół” (Elementy, VI.26) u Parmenidesa „jest ↔ nie jest” (B 2, w. 3).
EN
In our article we focus on an analysis of the structure of double negation in the poem of Parmenides, paying attention to the fragment B 2. The starting point for the analysis is the classification of varieties of negation contained in Diogenes Laertius (VII 69–70): negation, denial, privation and double negation. We provide an example of double negation as given by Diogenes: “Not (is not a day) ↔ it is a day”. In terms of the poetic expression the law of double negation serves to strengthen the goddess’ speech. However, in the context of Parmenides’ ontolog y, the law of double negation serves as an affirmation of ‘is’. Our goal is to give a detailed analysis of the structure of double negation. In the next step we introduce Euclid’s proofs by comparison. We show that all four forms of negation indicated by Diogenes occur in the Elements and there is a richer set of the linguistic forms used as an expression of nega- tion, including that of double negation. Finally, we show that Parmenides applies consciously the law of double negation, and the poem is the first philosophical text confirming the use of this law. In short, double negation can be summarized as follows: for the Stoics, in Diogenes Laertius (VII 69–70): “not (is not a day) ↔ is a day”; for Euclid: “not (is not-equal) ↔ is equal” (Elements I 6). “is not like that (... is not around ...) ↔ is around” (Elements VI 26); and in Parmenides: “is ↔ not (is not to be)” (B 2, v. 3).
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.