Very early in my career as a programmer, someone gave me advice that I needed to aim for the “ninety percent solution”, in other words, don’t waste time trying to get the perfect 100% solution.  Tom Cargill of Bell Labs provided a concise explanation: “The first 90 percent of the code accounts for the first 90 percent of the development time. The remaining 10 percent of the code accounts for the other 90 percent of the development time.”  This is analogous to the problem of distilling ethanol, getting it 97% pure isn’t too hard to do, but going beyond that takes enormous amounts of energy, and normally isn’t worth it (that is based on fuzzy memories of college chemistry class, so forgive any technical inaccuracies).

Recently I have read a number of articles which remind me that veganism can fall prey to this 90% rule.  There are a number of reasons why one may become vegan:  health, environment, animal welfare and animal rights (I exclude the “imitating a celebrity” reasons that PETA works towards, as that’s never a good reason for doing anything). The problem is that all but one of those reasons can only get you to 90%.

When I first became vegan it was for health reasons.  So when a friend of mine told me that “a little steak now and then won’t kill you,”  I had no good answer to this.  He was right.  I could eat a steak right now, and the impact on my long term health would be negligible.  In other words, there was little difference between being 100% or 90% vegan, when looking at the health arguments.  See How the Health Argument Fails Veganism for more about this.

Being vegan for environmental reasons suffers the same problem, as the mis-titled  article Veggieworld: Why eating greens won’t save the Planet shows.  If your concern is the environment, being 90% vegan is a pretty clear win.  But arguing for that last 10% can be very hard.  So “a little steak now and then won’t kill the planet.”

As the recent decades have shown us, the animal welfare arguments also suffer from this problem.  Someone who is vegan because of how animals are treated, when presented with the flesh of an animal who was free-range, fed organic feed, and was gently asphyxiated with a gold-lined silk scarf at the moment of orgasm, they would have a hard time refusing.  Thus we see the parade of now-ex-vegans marching into Whole Foods to buy their “happy meat” with a clear conscience.  Or so they think.

So, finally we arrive at the animal rights position.  Gary Francione presents the clearest, most consistent and most concise presentation of this position: “We have no moral justification for using nonhumans for our purposes.”  Here we have the 100% solution we’ve been looking for.  This is where we all need to start when we tell people why we are vegan.  And why they should be vegan.  And why you should be vegan.