"THE CONSTANT GARDENER,"

the 2005 film based on the acclaimed John le Carre novel, won an Oscar and critical plaudits for its account of corporate intrigue in sub-Saharan Africa. When I looked back at many of the glowing reviews this past week, I couldn't find one that raised any doubts about the plausibility of the plot, in which a large pharmaceutical company engages in a sinister conspiracy to test potentially lethal experimental drugs on unsuspecting, impoverished Africans and then cover up the deadly results.

I embarked on this quest after Pfizer's recent announcement that it was ending clinical trials of Torcetrapib, the hoped-for blockbuster drug that was designed to raise levels of the "good" cholesterol and revolutionize the treatment of heart disease, much as Pfizer's Lipitor became a huge bestseller (over $12 billion this year) while lowering levels of "bad" cholesterol. Just when did the big pharmaceutical companies like Pfizer become the pariahs of capitalism, ready candidates for the role of villain in big-budget thrillers, perhaps even the bad guys in the next James Bond adventure? When did pharmaceutical companies supplant cigarette and gun manufacturers in the pantheon of corporate perfidy?

Call me naive, but I always thought the drug manufacturers, in their quest to extend and enhance human life, were fundamentally doing a great deal of good. Nor did it bother me that they were being paid to do it. Indeed, when it comes to a cure for cancer, or diabetes, or AIDS, or heart disease, my feeling is: The more incentives the better.

The paradox of the drug companies is that what they do is so vital, so important, and so sought-after by so many that they have come to be viewed as public utilities, whose products should be, if not as free as the air we breathe, something close to it. At the very least, they should be regulated and policed, their profits curbed and their transgressions punished with draconian swiftness. So we have Congressional hearings into Merck's supposedly dastardly cover-up of the ill effects of Vioxx, when it was Merck that voluntarily stopped marketing it, even with many patients still pleading for it. You can bet there won't be any hearings into Pfizer's expenditure of over $1 billion to develop a drug that has now failed.

Even as I write this, I can picture the torrent of angry emails that will be my reward for saying something nice about Pfizer, or any big drug manufacturer for that matter. No company is perfect, and I acknowledge that Pfizer has made mistakes (like its short-lived and ill-fated effort to link sales of Torcetrapib to Lipitor). But Pfizer deserves a round of applause before this episode is forgotten amidst the next industry price-gouging frenzy. So do Pfizer shareholders, who suffered a swift 12% drop in the value of their shares for their willingness to finance the kind of risky research and development that just might have significantly reduced heart disease.

I do not speak as one of them. As I urged in this column after Merck's Vioxx debacle, I sold all my pharmaceutical stocks (including Pfizer) on the theory that it was simply too risky to own stocks in individual companies when a blockbuster drug might blow up with no warning.

Now it's evident that even a drug that's only in the research pipeline can fail, with dire consequences for shareholders. But I still have faith in the sector. The key is diversification. I own a health care exchange-traded fund, the iShares S&P Global Healthcare Sector Index Fund; a biotechnology ETF, the iShares Nasdaq Biotechnology Index Fund, and a health-care mutual fund, the Jennison Health Sciences Fund.

I wish I could recommend buying Pfizer shares as a way to encourage it to keep seeking new cures. Surely it has learned something from the Torcetrapib failure, and maybe it can still come up with an alternative medicine that will offer the benefits without the risks. Pfizer has a promising new chief executive and has embarked on a round of aggressive cost-cutting. Nonetheless, I see no reason to change my strategy of investing only in broad-based funds rather than individual stocks, even though Merck has performed quite well since hitting its post-Vioxx low. At close to $25 a share, Pfizer has already bounced back from the hit it took just after the Torcetrapib announcement. It boasts a nice dividend (3.82%) which seems secure given its strong cash flow, and I don't see much further downside risk in the near term. But as I've said before, I don't want to worry about the fate of any one drug manufacturer or any one blockbuster drug.