199,924 research outputs found
Writing and the rights of reality: usurpation and potentiality in Derrida, Plato, Nietzsche, and Beckett
No full textThe thesis critically evaluates Jacques Derrida's conferral of the rights of reality on writing, focussing on his theory of an arche-text in light of the speculative nature of this theory. The theory is initially considered in the context of Derrida's elucidation of the usurpatory status of writing within the Platonic and Nietzschean texts. This consideration reveals an admission of writing's usurpatory status by both writers while at the same time demonstrating their awareness of the intrinsically speculative nature of this view, the significance of writing lying in its ability to exteriorise the radically indeterminate status of consciousness m relation to reality rather than its ability to displace consciousness or reality The analyses, therefore, not only bring the Derridean hypothesis of a repressive or phonocentric metaphysical episteme into question but also exhibit the historical and philosophical role of potentiality in relation to writing, writing's ultimate significance lying in its capacity to exteriorise our existence as a mode of potentiality. Accordingly, in the second half of the thesis the Derridean theory of writing is countered with a specifically Aristotelian theory of the text as it is exhibited in the prose of Samuel Beckett, an author whose significance lies in his close alignment with Derridean theory within contemporary criticism. It is demonstrated that this identification has obviated an awareness of the significance of potentiality within the Beckettian text, his work consequently being appraised in the previously neglected context of Aristotelian metaphysics
Some uses of Plato in Achilles Tatius' Leucippe and Cleitophon
No full textThe aim of this thesis is to explore the relationship between Achilles Tatius' novel
Leucippe and Cleitophon and the Platonic corpus. I have searched for Platonic
allusions of various natures and purposes and grouped them into thematic chapters. I
have also compared instances of similar uses of Plato in contemporary authors in
order to classify both the individual cases and the place of Achilles Tatius' novel in its
literary environment, including the intended readership.
In my introduction I have argued that through the combination in his works of
philosophy and literary excellence Plato was an extremely important figure to the
Greeks of the second sophistic. However, despite the increasingly influential opinion
that Greek novel readership was not dissimilar to that of other works, the possibility
that the Greek novelists used Plato in a more than cosmetic fashion has been relatively
neglected. The uses of Plato on which I have concentrated are the employment of
Platonic names as allusions to their namesakes; Platonic narrative technique as the
model for the dialogue form and open-endedness of Leucippe and Cleitophon with
the integration of this technique into the broader question of the discrepancies
between the beginning and the end; the allusion to a particularly famous passage of
the Phaedrus in the name of the heroine; the repeated allusions to the Phaedran flow
of beauty, their purposes and the light they shed on the characterisation of Cleitophon;
and the Phaedran scene-setting, indulged in by many other writers, which Achilles
Tatius uses in two significant passages.
The conclusions I have reached are that Achilles Tatius uses Plato far more
extensively and imaginatively than hitherto realised; that such an intimate engagement
can shed light on other issues, such as psychological characterisation and the question
of humour; that Achilles Tatius wrote something of an "anti-Platonic" novel; and that
his work displays many similarities with other works whose sophistication is less in
doubt
Analysis of the variability properties of the stars in the PLATO Input Catalogue
No full textopenPLATO (PLAnetary Transits and Oscillations of stars) is the European Space Agency (ESA)’s mission scheduled for 2026 with the core goal to find and characterize rocky planets in the habitable zone of solar-like stars. In the first public release of the all-sky PLATO Input Catalogue (asPIC1.1) the stellar samples optimised for the mission’s scientific requirements have been defined and they include M dwarfs and FGK dwarf and subgiant target stars. The final observing strategy will be settled two years before launch; the optimal PLATO sky fields will be those that maximize the number of the most suitable targets for the detection of transiting exoplanets.
This work aims to evaluate the variability (intrinsic and extrinsic) of PLATO targets, in order to characterize them before the final sky fields and targets selection.
We exploited the largest whole-sky variability analysis to date based on coherent photometric, astrometric, and spectroscopic data from the third data release of ESA’s Gaia mission, Gaia DR3. We cross-matched by the unique identifier source_id all the PIC sources included in two wide sky regions at ecliptic latitudes |β| > 38◦, which envelope every allowed choice of the PLATO sky fields, with the Gaia DR3 variable sources categorized into 11 specific classes.
From this operation it resulted that the sources included in the considered sub-samples from the PLATO Input Catalogue can be distinguished into the following variability types:
planetary transits hosts, short-timescale variables, eclipsing binaries, solar-like stars, upper Main Sequence oscillators, RR Lyrae stars, Cepheids and long period variables. Their properties have been investigated and the light-curves for exemplary sources from each variability class have been extracted, showing the pulsating, rotating or binary nature of the targets.
We furthermore focused on the relevance of these sources for the PLATO space mission (in relation to both the primary objectives and the complementary science) and for future research prospects.PLATO (PLAnetary Transits and Oscillations of stars) is the European Space Agency (ESA)’s mission scheduled for 2026 with the core goal to find and characterize rocky planets in the habitable zone of solar-like stars. In the first public release of the all-sky PLATO Input Catalogue (asPIC1.1) the stellar samples optimised for the mission’s scientific requirements have been defined and they include M dwarfs and FGK dwarf and subgiant target stars. The final observing strategy will be settled two years before launch; the optimal PLATO sky fields will be those that maximize the number of the most suitable targets for the detection of transiting exoplanets.
This work aims to evaluate the variability (intrinsic and extrinsic) of PLATO targets, in order to characterize them before the final sky fields and targets selection.
We exploited the largest whole-sky variability analysis to date based on coherent photometric, astrometric, and spectroscopic data from the third data release of ESA’s Gaia mission, Gaia DR3. We cross-matched by the unique identifier source_id all the PIC sources included in two wide sky regions at ecliptic latitudes |β| > 38◦, which envelope every allowed choice of the PLATO sky fields, with the Gaia DR3 variable sources categorized into 11 specific classes.
From this operation it resulted that the sources included in the considered sub-samples from the PLATO Input Catalogue can be distinguished into the following variability types:
planetary transits hosts, short-timescale variables, eclipsing binaries, solar-like stars, upper Main Sequence oscillators, RR Lyrae stars, Cepheids and long period variables. Their properties have been investigated and the light-curves for exemplary sources from each variability class have been extracted, showing the pulsating, rotating or binary nature of the targets.
We furthermore focused on the relevance of these sources for the PLATO space mission (in relation to both the primary objectives and the complementary science) and for future research prospects
Study of stars with astrometric acceleration in the PLATO field
No full textopenLa missione PLATO, il cui lancio è atteso per la fine del 2026, rappresenta l'ultima frontiera nello studio e nella ricerca di esopianeti: essa permetterà di individuare e caratterizzare pianeti rocciosi nella Zona Abitabile di stelle simili al Sole. In attesa dell'effettivo rilascio di dati da parte di tale missione, questa tesi si pone l'obiettivo di identificare e caratterizzare i target con accelerazione astrometrica presenti nel primo campo a puntamento lungo osservato dal satellite.
Avendo questa finalità come scopo ultimo, sono state selezionate dall'ESA Gaia Archive tutte le stelle presenti nel campo LOPS2 di PLATO. Nell'analisi ci si è concentrati sugli oggetti caratterizzati da un rapporto segnale-rumore dell'anomalia di moto proprio (derivata dalle missioni Gaia-Hipparcos su una baseline di 24.75 anni) maggiore di 3; successivamente sono stati esclusi i sistemi binari già noti, impiegando appositi match con numerosi cataloghi disponibili in letteratura. I candidati rimasti sono stati confrontati con cataloghi noti di esopianeti e nane brune, ottenendo 15 corrispondenze di rilievo, di cui quattro analizzate più nello specifico. Si deve menzionare in questo contesto anche la M dwarf GJ 2060, un sistema binario stretto che lascia aperta la possibilità della presenza di un compagno planetario.
I risultati ottenuti rappresentano un contributo rilevante in vista della missione PLATO. In particolare, da un lato permettono di identificare oggetti che già ospitano o potrebbero ospitare pianeti giganti di lungo periodo; dall'altro permettono di identificare stelle confermate o sospette binarie, la cui natura andrà presa in considerazione sia nella validazione e conferma di eventuali candidati a pianeti transitanti, sia nello studio e caratterizzazione di pianeti in sistemi binari
Omnia Platonis opera
No full textImpressum aus Kolophon: "VENETIIS IN AEDIB. ALDI, ET ANDREAE SOCERI MENSE SEPTEMBRI. M. D. XIII."Mit Druckermarken (Titelblatt u. letzte Seite)Auf Titelblatt hs. Besitzereintrag: "Sum Amerbachior[um]
Kinematics characterization of targets in the PLATO Input Catalogue
No full textopenPLATO (PLanetary Transits and Oscillations of stars) is a mission of the European Space Agency (ESA) which will launch in 2026, with the ambitious goal of discovering a large number of Earth-like exoplanets orbiting around Sun-like stars. To achieve its objectives, PLATO will observe hundreds of thousands of FGK dwarfs and subgiants and M stars. The first observing field has been recently selected and contains about 180 000 targets.
The work which is presented in this master thesis is framed in the context of the PLATO mission and in particular in the necessary preliminary analysis of the targets, needed both for the optimization of the mission as well as for the interpretation of the mission results. In particular, in this work I performed a 6-D (positions and velocities in the Milky Way) kinematics investigation of the targets in the PLATO Input Catalogue (PIC), namely the catalogue containing the targets that will be observed. The main aim of this work is to place PIC targets in the context of the Milky Way, so that, when PLATO will start discovering exoplanets, it will be possible to study the relation between planets and the Galactic environment in which they formed.
To perform such study, I cross-matched the PIC with catalogues containing the data from other surveys, such as Gaia DR3 and RAVE, in order to extract information about the positions, the proper motions and the metallicity of the targets. Analyzing these data, I was able to classify the targets in terms of the stellar components of our Galaxy: thin disk, thick disk and halo.
Furthermore, I showed and briefly discussed the stellar properties of the targets, such as radius, mass and effective temperature, in the context of each stellar component.
Finally, I cross-matched the PIC with other relevant catalogues, such as the TESS Objects of Interest catalogue, the VSX catalogue, which lists variable objects, and a recently-created Gaia-based open clusters catalogue in order to identify peculiar targets and evaluate how many and which targets belong to known open clusters.PLATO (PLanetary Transits and Oscillations of stars) is a mission of the European Space Agency (ESA) which will launch in 2026, with the ambitious goal of discovering a large number of Earth-like exoplanets orbiting around Sun-like stars. To achieve its objectives, PLATO will observe hundreds of thousands of FGK dwarfs and subgiants and M stars. The first observing field has been recently selected and contains about 180 000 targets.
The work which is presented in this master thesis is framed in the context of the PLATO mission and in particular in the necessary preliminary analysis of the targets, needed both for the optimization of the mission as well as for the interpretation of the mission results. In particular, in this work I performed a 6-D (positions and velocities in the Milky Way) kinematics investigation of the targets in the PLATO Input Catalogue (PIC), namely the catalogue containing the targets that will be observed. The main aim of this work is to place PIC targets in the context of the Milky Way, so that, when PLATO will start discovering exoplanets, it will be possible to study the relation between planets and the Galactic environment in which they formed.
To perform such study, I cross-matched the PIC with catalogues containing the data from other surveys, such as Gaia DR3 and RAVE, in order to extract information about the positions, the proper motions and the metallicity of the targets. Analyzing these data, I was able to classify the targets in terms of the stellar components of our Galaxy: thin disk, thick disk and halo.
Furthermore, I showed and briefly discussed the stellar properties of the targets, such as radius, mass and effective temperature, in the context of each stellar component.
Finally, I cross-matched the PIC with other relevant catalogues, such as the TESS Objects of Interest catalogue, the VSX catalogue, which lists variable objects, and a recently-created Gaia-based open clusters catalogue in order to identify peculiar targets and evaluate how many and which targets belong to known open clusters
Gender, Spirit and Soul: the differences in attitude of Plato and Augustine of hippo towards women and slaves
No full textThis thesis will look at the changes brought about in the perception of women's role in society by the advent of Christianity. The early chapters will discuss the actual status of women in ancient Graeco-Roman and Jewish society, so far as that can be discovered; followed by St Paul's views on women, which heavily influenced St Augustine. I shall then examine the status assigned to women and slaves by Plato in his two outlines for ideal societies, the Republic and the Laws, and shall finish with an examination of Augustine's attitudes to women and slavery. Plato believed that intelligent women were just as capable as men of achieving the philosophical ideal, and he believed that there would be many intelligent women in any given society. Many of Augustine's Letters are addressed to 'holy women", though he was reluctant to accept that these women were not exceptional. Augustine had many female correspondents, most but not all of whom were consecrated virgins or chaste widows. It is quite clear that Augustine believed that these women could achieve salvation on their own account, and also that he respected the intellect of some of them. However, even these women were to live subdued, enclosed lives. In the City of God he follows Paul in circumscribing the actions of women, but his estimation of their intellect is consistently higher than Paul's. The major difference between Plato and the Christians on this issue was that for Plato, sex was a part of normal life, and indeed essential to the continuation of the State; whereas for Christians it had become a problem and a hindrance to salvation. Neither Paul nor Augustine considered it necessary to combat slavery, probably because they were more concerned with securing the afterlife than with correcting conditions in this life
The unity of phaedrus
No full textMy dissertation will discuss the whole argument of Plato's Phaedrus according to a particular approach I have adopted. This approach deals with three problems unique to this dialogue: (a) the subject of Phaedrus, (b) the influence of Phaedrus as the interlocutor and (c) the critique of written works. To solve these problems, I will divide the subject into four stages and examine each stage. Finally, the question "what unites Phaedrus?" will be answered. There are four stages, each corresponding to a chapter. Chapter 2: (1) In the first part of this dialogue, what is argued? Chapter 3: (2) In the second part of this dialogue, what is argued? Chapter 4: (3) How do the characters converse on those topics? Chapter 5: (4) What does the author, Plato, intend to express by writing this dialogue? Chapters 2 and 3 will discuss problem (a), chapter 4 is on problem (b) and chapter 5 is on (c). As the arguments proceed through its stages, I think we may acquire the more comprehensive and transcendental view: the view of the author. Through this dissertation, we shall seem to understand the main subject: that the best kind of companionship (the aspect of love) consists in inquiring into truth by engaging in logos (the aspect of rhetoric) [from chs.2 and 3]. And what Plato wants to tell us by writing this dialogue is to show a picture of a philosopher which Plato regards as true [ch.4] and to attempt to provoke us the readers, in order to encourage us to practise this activity in the way that Socrates does [ch.5]. As we leave the dialogue, we are supposed to embark on philosophical search for ourselves
Stoic unformed substance and old academic ontology
No full textThis thesis examines the influences on the Stoics' development of their material principle. The thesis argues that the reasons for the Stoics' conceiving of a material principle as they did actually have their origins in metaphysical speculation rather than physics.
While the natural philosophy of the Ionians, as interpreted by Aristotle and his followers, no doubt furnished the intellectual background for a persisting material substrate of all sensible change, it is in fact the concerns of Plato and his early followers with the non-sensible that exert the strongest influence on the Stoics.
The thesis examines the concepts of space and matter in the Timaeus ultimately rejecting this work of physics as central to the development of Stoic thought on matter. Rather it is the metaphysical doctrines of Plato and his successors, and the use they make of an incorporeal matter, that exerted the greatest influence on the Stoics and their material principle. The interpretation of Platonic metaphysics argued for in the thesis, based on the Unwritten Doctrines and the Old Academy's teachings, challenges the majority opinion of the English speaking community; and as a result offers a novel understanding of the relationship of Stoicism to Platonic metaphysics.
The thesis concludes that it is likely that the early Stoics developed their doctrine of a material substrate in the particular way they did because of the tendency in the Old Academy to simplify the doctrines of Plato. This simplifying tendency comes to a head in the early Stoics with the ultimate reduction of the Old Academic system of hypostases, making use of active and passive principles at various levels of reality, finally ending in one level of reality and a simple two principle system
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