Today, Ryanair has threatened to sue the government over the security measures that have recently been imposed at airports. Since a plot to detonate bombs on planes traveling from the UK to the US was uncovered a few weeks ago, air passengers have faced tight restrictions on what hand-luggage they are allowed to carry, and stricter checks than were previously in place when boarding.

The measures have made air travel from the UK extremely difficult. Passengers have endured long delays, and many flights have had to be cancelled, negatively affecting airlines. A Ryanair spokesperson argued that the measures are unnecessary, and said that unless they were lifted Ryanair would be seeking compensation from the government for imposing them.

To support this claim that the security measures are unnecessary, the spokesman made a comparison with the 7/7 Tube bombings. After the bombings, he pointed out, the government got the Tube service back to normal within a matter of days. There is therefore no reason, he inferred, for the current security measures at airports to continue weeks after the plot to bomb aircraft was uncovered; things should be back to normal by now.

This argument overlooks important differences between the two cases; it draws a weak analogy. For example, the Tube bombings did not involve the discovery of any new threat, and so once the damage done had been repaired and the crime scene examined, things could return to normal. The discovery of the recent terrorist plot, however, raised a new danger: the possible use of liquid explosives. It therefore required new security measures to be introduced indefinitely.

This difference between the cases that the Ryanair spokesman compared means that the comparison can’t support the conclusion that he drew from it.

Among Jesus’ most famous teachings are the Beatitudes, a series of sayings beginning “Blessed are the…” and ending by naming a group of people who, by worldly standards, certainly don’t seem to be blessed. Groups singled out as being blessed include the meek, those who mourn, and those who are persecuted for righteousness (along with the peacemakers, the hungry, the pure of heart, etc.).

One way of reading the Beatidues, described but not endorsed here by Dave Smith of Online Opinion, is as a prescription of how we ought to be. If we are to be blessed, on this view, then we must seek to imitate the blessed in the Beatitudes. The meek are blessed, so we must seek to be meek; those who mourn are blessed, so we must seek to mourn; those who are persecuted are blessed, so we must seek out persecution. To adopt the televangelist slang, the Beatitudes contain ‘Be-Attitudes’, attitudes that we ought to adopt.

This reading goes beyond the text, and it does so via a logical fallacy.

Jesus describes people who are blessed. Everyone in each of these groups, he suggests, is blessed. Being a member of one of these groups is a sufficient condition for blessedness.

That being a member of one of these groups is a sufficient condition for blessedness does not imply that being so is a necessary condition for blessedness; it does not imply that only members of these groups are blessed. And it certainly doesn’t imply that only members of all of the groups are blessed. Blessedness may well come to other people too.

We must not confuse necessary and sufficient conditions. Though the meek, the mourners, and the persecuted may be blessed, for all that the text says our route to blessedness may have nothing to do with any of these attitudes. The Beatitudes are not ‘Be-Attitudes’ at all.

On August 16th 2006, The Sun newspaper ran the story Playboy Prince Cops a Feel (the current version has been amended in light of criticism). In it, Harry was accused of drunkenly groping friend Natalie Pinkham at the Boujis nightclub while his girlfriend Chelsy Davey was out of the country.

A photo of the Prince grabbing Natalie’s breast was printed in support of this claim, along with various foreboding comments about the trouble he’ll be in when Chelsy returns.

Here’s the picture. Does it prove The Sun’s allegation?

For relevance, it’s pretty good. In the picture we see Harry, with his hand where it shouldn’t be. We have to take The Sun’s word about Harry having a girlfriend who’s out of the country, but the important elements of the claim are represented in the picture.

For selectivity, there aren’t any problems. Even if this is the only moment that Harry was out of line, that’s enough to support The Sun’s claim that he’s been misbehaving. One transgression would be enough to land him in trouble, and we see that in the photo.

The main weakness of the photo as evidence relates to significance. It’s extremely difficult to tell where it was taken; is that Boujis, or somewhere else? More importantly, it’s very difficult to tell when it was taken; is it a recent photo, or one that was taken a while ago? A certain amount of interpretation is necessary to get from the image to the claim it’s supposed to support.

Later in the day, Clarence House responded to the story on behalf of the Prince. They protested that the photo was taken three years ago–before Harry and Chelsy got together–and asked The Sun to correct their story. In support of this, they pointed out that Harry, and William who is in the background of the picture, both have different hair-styles now to those in the photo.

Beware of taking photos, particularly those in tabloids, at face value.