As Epicurus once said:
“death, the most frightening of bad things, is nothing to us; since when we exist, death is not yet present, and when death is present, then we do not exist”.
According to Timothy Williamson in Modal Logic as Metaphysics (MAM), the dispute between permanentism and temporaryism constitutes a dimension of the problem, yet to be defined, where the dispute of necessitism and contigentism impinges on matters of moral and emotional concern. The problem: “that some hold that what is good or bad for one consists in one’s having experiences of relevant kinds.” (p.29).
In chapter two from MAM Williamson points out that the metaphysical dispute between contigentism and necessitism turns out to be connected with technical issues in quantified modal logic – Barcan formula (BF) and its converse (CBF). Williamson tries to show how these formulas emerged in the twentieth-century logic and then tries to explain how they gradually came to seem metaphysically problematic for the contigentists, who insistently tried to avoid them.
The Barcan formula and its converse appeared in the context of logical positivism, where “all logic is good” and “all metaphysics is bad”. But with the mix of some philosophical reasons and technical developments in logic (e.g. BF and CBF), such separation became hard to maintain.
Barcan Marcus formulates her axiom schemata with strict implication as the main connective and by doing that all their instances make necessitated claims. The first schema Williamson shows is distinctive for the interaction of modal operators and quantifiers:
Our metalanguage substitutes an individual variable for v and an open or closed formula for A. If we think, as we may, of A as stating a condition on the value of v, then we can read (I) as saying that “(…)necessarily, if there could have been an individual that satisfied the condition, then there is an individual that could have satisfied the condition.” (p.32).
One of Barcan’s paper (1946) main roles is to permit the derivation of the result of putting strict implication for material implication in the non-modal principle:
One thing to remember is that the Barcan formula has come to be used in its unnecessitated variant, differing from (I) – lack of parenthesis:
more to come soon, lazy and full of work…
Nice cheat sheet on simple quantification, conjunctive combinations and some other cute things that make logic so beloved among philosophy students. To download it, just click on the link below…
Uma das coisas mais irritantes que podem acontecer quando você está montando um projeto com ruby on rails no heroku é ao tentar usar o
git push heroku master
aparece a desgramada mensagem de erro:
Permission denied (publickey).
fatal: The remote end hung up unexpectedly
Mas não se apoquente meu caro, a solução é simples ~
Através do terminal vá até à pasta do seu projeto:
E em seguinda insira o seguinte código:
heroku keys:add ~/.ssh/id_rsa.pub
Agora a sua key será autenticada normalmente, pode mandar ver:
git push heroku master
Great talk from professor Luciano Floridi, director of the Internet Studies Institute at Oxford University, about how reality is becoming AI friendly. The video was recorded during the Philosophy & Theory of Artificial Inteligence conference.
Nanotechnology, the Internet of Things, Web 2.0, Semantic Web, Cloud computing, motion-capturing games, smart phones apps, GPS, Augmented Reality, Artificial Companions, drones… is there a unifying perspective from which all these ICT phenomena might be interpreted as aspects of a single, macroscopic trend? Part of the difficulty, in answering this question, is that we are still used to looking at ICTs as tools to interact with the world, when in fact they have become environmental forces, which are creating and shaping (that is, re-ontologising) our reality, more and more pervasively. To put it briefly, the answer may lie in realising that ICTs are enveloping the world – In robotics, an envelope (also known as reach envelope) is the three-dimensional space that defines the boundaries that the robot can reach.
UPDATE: Unfortunately the academics who made the video – and supposedly university staff should fight for information freedom and knowledge dissemination – recently set the video as ‘private’ on youtube. Oh boy, philosophers and academics in general are the kings of Performative Contradiction.
A link to some of Floridi’s works.