venerdì 7 dicembre 2012

Australia, the ethics courses continue, but will be "hidden" from the parents

Adrian Piccoli
The ethics courses in the schools of New South Wales, Australia, will continue, but the parents will be informed of their existence only after having renounced the religion class.

Adrian Piccoli, Minister of Education, has accepted the opinion of a committee, according to which ethics courses will be maintained as an alternative to the course of  Special Religious Education, but considers it appropriate to disclose to parents the existence of such courses only after they have expressed their intention to opt-out of the religion classes:
"Ethics classes can be promoted," said Piccoli, "but what it means in a technical sense as such, that when parents are asked the question 'do you want your child to do special religious education', that's the first question that gets asked and if they say no then they say, 'well you can either do other things or you can do ethics classes'."
Greens MP John Kaye has criticized this choice:
"Nothing in the Education Act, which was amended in late 2010 to include the right to have access to ethics, nothing in that act at all say we have to discriminate against ethics in this way." "(There's no need) to keep it hidden, in the back drawer, so that nobody knows about it at the time they make the decision."
The news of the continuation of the classes was taken with relief by Simon Longstaff, a member of the St James Ethics Centre, the institution in charge of organizing the courses. Longstaff, however, was surprised by the decision to "obscure" the courses:
"There's something curious about not even telling people that an option exists until they have chosen something else. [...] It's a bit like having ethics classes within a sealed section within a magazine."
The St James Ethics Centre recruits and organizes volunteers for the lessons, attended by 7000 students. The ethics courses, as those of religion, are paid for through donations; donations to religious classes, however, are exempted from taxes, and the St James is trying to get the same recognition for donations in favour of ethics courses.

The ethics courses were introduced in schools of New South Wales in 2010, after a period of experimentation. as an elective alternative to courses on religion (also optional). At the time they encountered the opposition of the association that brings together the managers of the various religious courses. Six months after it was revealed that almost half of the students had left the religious courses to attend to those of ethics. The success of the Australian ethics courses brought, a few months ago, to the proposal to establish similar courses in France.

«Parents 'left in the dark' about ethics classes», ABC News, December 5th, 2012.

martedì 4 dicembre 2012

Betting on horses and the resurrection of Jesus (II)

Thomas Bayes (1701–1761)
In the last article I used a horse racing / mathematical problem to introduce Bayes' theorem in its odds-based form, ie the one using the ratio of the probability p that an event 'A' occurrs and of the probability 1-p that it does not occur: O (A) = p / (1-p).

At the end of that same article, I also promised a connection between this formulation of Bayes' theorem and the resurrection of Jesus. Obviously the key to this promise is found in the article immediately before, "On the validity of the testimony of the apostles about the resurrection of Jesus", in which I explained why the testimony of the apostles of Jesus about his resurrection is not an evidence strong enough to accept as true the hypothesis that a human being has risen from the dead. Now, with the help of Bayes' theorem, we can calculate how unlikely this hypothesis is.

Bayes' formula

First a small summary. Let O (H) be the odds of the hypothesis 'H' regardless of the occurrence of event 'E', P (E | H) the probability of the event 'E' when the hypothesis 'H' is true, P (E | ¬ H) the probability of the event 'E' when the hypothesis H' is false, and O (H | E) the odds of the hypothesis 'H' when event 'E' is taken into account; then Bayes' theorem is expressed in the following form:
O (H | E) = O (H) * P (E | H) / P (E | ¬ H),
that is the odds of hypothesis 'H' when observing event 'E' are equal to the odds of hypothesis 'H' regardless of the observation of 'E' multiplied by the likelihood ratio, the ratio between the probability to observe the event 'E' when the hypothesis 'H' is true and the probability of the event 'E' when the hypothesis 'H' is false. Through this ratio it is possible to update the odds of a hypothesis following the observation of an event.

The subject of the inquire

Our hypothesis 'H' is "Jesus was truly risen", meaning that Jesus was a human being and that his body returned to life. We have no direct observation of this resurrection, but we observed the event 'E' "the apostles of Jesus were witnesses of the resurrection".

The question we ask ourselves is what is the value of O (H | E), what are the odds that the hypothesis "Jesus is truly risen" is true, taking into account the event 'E' "the apostles of Jesus were witnesses of the resurrection". Applying Bayes' theorem, we find that this quantity depends on three factors:
  1. the odds that the hypothesis 'H' is true, regardless of the testimony of the apostles, O (H);
  2. the probability that the apostles would have been witnesses of the resurrection if Jesus was really risen, P (E | H);
  3. the probability that the apostles would have been witnesses of the resurrection if Jesus was not really risen, P (E | ¬ H).

How many people have lived on Earth?

What is the probability that Jesus rose from the dead, regardless of the testimony of the apostles? Given that this testimony is the only evidence of such an event, it is not unreasonable to think that the resurrection of Jesus has in general the same probability of occurrence of the resurrection of every other human being.

domenica 2 dicembre 2012

Betting on horses and the resurrection of Jesus (I)

A friend of yours, a real fanatic of horse races, has convinced you to follow him at the racecourse on a racing day. While you are waiting for the beginning of the races, you decide that, after all, a small betting would be fine. So you read the program of the first race, and the name of a horse comes to your attention: Soldatino!

You ask your friend if Soldatino is a good horse, but the answer is negative: in 105 races in which it participated, it "showed" (i.e., it arrived within the first three places) in just 7, that is, for each time it showed it did not for 14 times! Well, not exactly the favourite of the race...

Seeing your disappointment, your friend tries to get you a bit on the moral: "During the night it rained a lot, so the ground is very heavy." Noting your quizzical expression, your friend tells you that in 70% of the races in which Soldatino showed, the ground was heavy, and in those races in which it came in fourth or worse, the ground was heavy in 10% of cases.