This is, of course, a brilliant example of the false logic: "Doing X in circumstance Y is a bad thing. Therefore doing X in any circumstances is a bad thing."

Now why do people think like that?

Further more, do the people who think like that have a greater chance of becoming successful politicians (or journalists)?

Possibly even worse, and slightly different, is it true that a large proportion of sucessful politicians (and journalists) think like that?

What are the favoured careers of people who do not think like that?

[Note: I have considered, briefly in posing my questions, whether I am thinking "like that" now. I hope I've avoided the trap.]

Best regards

Nigel, in the case of DDT there was no bad thing, even all these years later, the evidence for any downside is very doubtful. The only problem is, that like antibiotics, over use leads to a build-up of resistance. However on your main point, Rachel Carson’s book seemed to trigger a herd reaction. In nature this is a vital survival tactic. Presumably it still exists in us. Herd instinct requires immediate reaction and definitely no thinking. Politicians and perhaps Journalists are necessarily perhaps those people must attuned to the herd. They then wish to be seen as leaders so rush to lead the reaction of the herd. Only then do they start to think, but unfortunately use their intellect to justify their position as herd leaders.

David Roberts

In answer:
1 People think like that because its easy.

2 No, politicians and journalists have to be able to get other people to think like that so must think thoughts of slightly more complexity.

3 No, see above.

4 Anything that they want as they have not been manipulated by the politicians and journalists into oversimplifying their thinking.

I wrote:

This is, of course, a brilliant example of the false logic: "Doing X in circumstance Y is a bad thing. Therefore doing X in any circumstances is a bad thing.

David Roberts writes, I think not entirely in agreement with me:

Nigel, in the case of DDT there was no bad thing, even all these years later, the evidence for any downside is very doubtful.

Accordingly, I'll post an even worse variant of false logic:

"This is, of course, an example of further false logic: "Doing X in circumstance Y is allegedly a bad thing, though actually it is not. Therefore, not only is doing X in circumstance Y is a bad thing (thought lacking evidence for this), but doing X in any circumstances is a bad thing."

Actually, the combination of two false logics does not strike me as any sort of improvement, either in false logic or in criticism thereof.

I feel mandrill had a better response to my philosophical case, and to my questions as to whether politicians (and journalists) are more prone to this particular false logic than are others.

Best regards

Nigel's got it right. I have begun to think, lately, that journalists cannot hold a thought that runs longer than a sound bite, so "X is bad in circumstance Y" becomes "X is bad" in their sound bite brains. Especially when that result fits with their ordained knowledge.

David Roberts,

the evidence for any downside is very doubtful.

I'll presume you're not joking and equate your reasoning practices with those of journalists. For you the false logic would read -

Doing X in circumstance Y is a good thing. Therefore doing X in any circumstances is a good thing.

DDT definitely has many undesirable effects in a great many situations that make its reintroduction something to be done with a reasoned caution.

Thank you Midwestener. That adds clearly and usefully.

Best regards

Midwesterner,

"DDT definitely has many undesirable effects in a great many situations."

I would hope that after reading this link you would be less definite.

http://www.junkscience.com/ddtfaq.htm

David Roberts

David Roberts, even on the link you gave me,

"There is persuasive evidence that antimalarial operations did not produce mosquito resistance to DDT. That crime, and in a very real sense it was a crime, can be laid to the intemperate and inappropriate use of DDT by farmers, espeially cotton growers. They used the insecticide at levels that would accelerate, if not actually induce, the selection of a resistant population of mosquitoes."

[Desowitz, RS. 1992. Malaria Capers, W.W. Norton & Company]

points out problems with DDT usage.

Also, the site you link, junkscience, appears to be guilty of some junk science of their own. The egg shell thinning effect is selective with chickens being unaffected yet some waterfowl highly vulnerable , but junk science seems to be getting most of it's data from poultry research. Also, what's with the antiquated research? I thought the 1977 in my link was old but most of what junk science is presenting is older still.

And I used your "junkscience" link to search some of the authors they quote and hopefully to find something a little more recent. I found this paper that was written to contradict this anti-chemical stance. It introduces its purpose by saying -

"The conclusion of this article [the one being rebutted] is that a very wide range of wildlife species is now threatened by a diverse assortment of synthetic chemicals in the environment. Their effects are initially hidden but in the longer term reproductive abnormalities and disruptions in other essential life processes result from the "stealth damage caused by interference with endogenous messengers" (Smolen and Colborn 1997:10).

They then go on to show how this is far from proven and the study has not been properly controlled. When reading their rebuttal, remember that DDE is the persistent product of DDT and causes most of the consequences.

To conclude, I stand by my original statement that DDT should be reintroduced with 'reasoned caution'. It has the potential to do great things when used appropriately and cautiously. I think your total denial of any negative effects does not meet that criterion.

Midwesterner, I find your comments entirely reasonable. In my view however, the crime was the total banning for many years of DDT, the best known defence against malaria. Coming back to a previous point, it was not based on any sound evidence but on hysteria. The current change of heart to use DDT, as you mention, confirms the wrong-headedness of the ban. You may say this is easy to say in retrospect, but admitting the error and learning from it must be the aim, but what do we see now but the demonising of CO2 based again on very poor science. Are we, as a society, learning?

David Roberts

Midwesterner one other point, I don't do "total denial" but only probabilities. In mathematics and logic certainty is built in, but in life and science, not.

David Roberts

DDT, while very useful for killing selected critters, is also selective for critters we don't want killed. It also endures enough to climb up the food chain and kill off things we really don't want killed. And durable enough to stay at it for decades.

It seems pretty basic to me that it must be kept out of the food chain. Perhaps by restricting its use to sterile, non-draining systems, ie swimming pool=okay, pond=not okay or nets&screens=okay, orchard=not okay. And of course, when drained the pool's water would need to be processed to remove it.

I can tell you from experience, because I live on a hill between a marsh and an entirely lilly covered lake, that dragonflies and bats are by far the most effective skeeter beaters. During peak mosquito season we have swarms of dragonflies and yet I can walk in the evening without getting a single mosquito bite. THere is occasionally a brief lag between a hatching of mosquitos and a hatching of dragonflies & damselflies and during this period, we learn how truly bad things wood be without natural predators. We also have a colony of bats living in our barn. Anything that harms these predator populations makes the problem worse, not better. Further more, it is very difficult to not accidently breed for resistant mosquitos even when being careful with a non co-evolving control agent like DDT.

I encourage people to read the link I gave earlier, and understand while DDT is apparently very safe and effective in certain uses (like nets and screens) it is by no means the harmless victim of bad press that junk science implies.