The definition of socially responsible investing is open to interpretation, though it implies a higher moral level: investing to make the world a better place. The orthodox interpretation -- the one that pops most to mind -- conjures images of a cleaner, healthier, safer world.

I tend to stray from orthodoxy, so cleaner, healthier, safer don't necessarily pop to my mind. Particularly if cleaner, healthier, and safer are achieved through subsidies, tariffs, and quotas. My definition of socially responsible investing satisfies legitimate, legal demands, with profit being the overriding motive. Therefore, I feel perfectly justified in slotting the following stocks in the "socially responsible" category.

Heterodoxy over orthodoxy
Taste matters. Eating isn't only about nutrition. At least, that could be the mantra of CKE Restaurants (NYSE:CKR), a fast-food chain that operates, franchises, or licenses 3,116 restaurants under the Carl's Jr. and Hardee's monikers. CKE's bailiwick is tasty, gut-busting fare. Its menus are replete with burgers broaching 1,000 calories. CKE's shares have suffered a mild cardiac infarction; they now trade at $10 and change, from around $23 a share in mid-2007, thanks to sales hitting a blockage at $1.5 billion per annum.

But management is attempting to clear the pipes with a push into China, where it recently opened its first restaurant. The plan is to open 100 restaurants within the next eight years, with the potential for 1,000 restaurants further out. To assuage any immediate angina pains, CKE pays a $0.24-per-share annual dividend, yielding around 2.3%.

If you prefer pork to burgers, then thank Smithfield Foods (NYSE:SFD) for keeping the market well-stocked. Smithfield is the world's largest pork processor and hog producer. Its U.S. operations process (OK, slaughter) 31 million hogs annually.  A series of acquisitions has doubled sales this decade, to $12.5 billion in fiscal year 2009. At the same time, long-term debt has ballooned to $3.3 billion.

The company's shares have lost nearly two-thirds of their value since peaking in mid-2007. But the lower price should create opportunity; demand for pork remains steady and margins should improve as Smithfield makes headway in the higher-value processed-meat market.

Hogs aren't usually dropped with a gun, but other animals are, and many have undoubtedly been dropped by the output from Sturm, Ruger (NYSE:RGR), a leading manufacturer of rifles, shotguns, pistols, and revolvers. It's a mature business, though Ruger's sales were up 16% to $181 million in 2008 because of concerns over the anti-gun leanings of the current administration.

Ben Graham aficionados will appreciate Ruger's balance sheet: no long-term debt, and current assets more than twice current liabilities. Ruger's shares have doubled year to date, but I still think enough fear and enough organic demand remain to lift those shares higher.

A few irresponsible gun owners will imbibe while target-shooting. Shame on them. But if they prefer premium booze during their outings, chances are they've quaffed the output from London-based Diageo (NYSE:DEO). Its Tanqueray, Jose Cuervo, Baileys, and Johnnie Walker brands occupy the No. 1 positions in their respective categories, while its Smirnoff brand occupies the top spot as the world's premium spirit.  

Like firearms, booze is a mature industry, but you'd hardly know it by Diageo's full-year sales, which rose 15% in fiscal year 2009. Since 2006, Diego has averaged cash flow of more than $5 a share, more than enough to fund its very generous dividend. What's more, Diageo is trading at a 33% discount from its all-time high, set in late 2007.

A cigarette is the natural accompaniment to a cocktail. Philip Morris International (NYSE:PM), the March 2008 spinoff of Altria (NYSE:MO), is a world leader in providing nicotine fixes. Philip Morris International retains many of the endearing qualities of the old Philip Morris: namely, the international rights to the very popular Marlboro brand and the ability of that brand to generate gobs of cash to fund a very generous dividend. On that front, Philip Morris International recently raised the quarterly dividend 7.4%, to $0.58 a share, to yield 4.8% when annualized.

Your cash flow matters most, and Philip Morris/Altria has a history of adhering to that dictum.

Finally, there's "better living through chemistry" -- chemical-giant DuPont's (NYSE:DD) 1970s catchphrase. But not everyone agrees. According to the Political Economy Research Institute at the University of Massachusetts, no one messes up the planet more than DuPont, which was slotted in pole position in PERI's "The Toxic 100." But that's PERI's opinion.

DuPont continues to make money in pigments, building materials, chemicals, and herbicides, evinced by recent quarterly results. Meanwhile, DuPont continues to fund a very remunerative dividend, currently paying $1.64 per annum to yield more than 5%. What's more, DuPont's on sale; its shares are trading at a 40% discount to their five-year high.

Tongue not-so-in cheek
So there's one heterodox investor's SRI portfolio. It's not for everyone, to be sure -- but then again, the typical SRI portfolio isn't for this heterodox investor.

Fool contributor Stephen Mauzy, CFA, owns shares in DuPont. He's the author of the upcoming book The Wealth Portfolio. Diageo is a Motley Fool Income Investor pick. Philip Morris International is a Motley Fool Global Gains selection.The Fool has a disclosure policy.