We all know the story of when a man provoked Rabbi Hillel to sum up the whole Torah while standing on one foot. His simple reply: “What is hateful to thyself do not do unto thy neighbor. That is the whole Torah. The rest,” he famously asserted, “is commentary.”

Seems easy enough. But this raises an obvious question: Just who exactly is our neighbor?

Are animals our neighbors, and if so, how can we better reflect that in our lives?

Most Americans in 2010 will argue that of course we should include animals in our sphere of moral concern. After all, there’s plenty of evidence that God too is concerned about His creatures. Whether it’s the prohibition on preventing an ox from eating while working a field (Deuteronomy 25:4), the proverb asserting that “the righteous man regardeth the life of his animal” (Proverbs 12:10), or most poignantly the Jewish concept of tsa’ar ba’alei chaim, the obligation not to harm animals, one need not look far for faith-based underpinnings of our view that tormenting animals is unethical.

But while we may all agree that animals deserve to be treated well, unfortunately few of us apply this principle beyond our personal interactions with our dogs and cats. In fact, most of us buy food products derived from animals who were treated so deplorably that their abuse could hardly have been envisioned by those alive in Biblical times. These animals aren’t abused because those in animal agribusiness are sadistic. They’re abused because we pay others to carry out the violence on our behalf.

As just one example, most egg-laying hens are confined in cages so restrictive they can’t even spread their wings. Each of them has less space than a sheet of paper on which to live for more than a year before she’s slaughtered. It really is hard to imagine a more miserable existence.

Yet, when we buy eggs from caged hens—the vast majority of eggs produced in the country—we support that kind of cruelty. And again, eggs are just one example. Factory farming is the norm, not the exception, when it comes to animal agribusiness these days.

The good news is that each one of us can do better when it comes to applying Hillel’s admonition in modern times to our relationship with the nonhuman inhabitants of the world. As Repair the World points out, we can stand up for animals every time we sit down to eat. By making better food choices, we can begin to more closely align our values of mercy and respect within our daily lives.

What we eat may in one sense seem like a personal choice, but in another sense it’s clear that our food purchases actually have a huge impact on others. We can choose compassion, or we can choose to inflict cruelty. We can choose mercy, or we can choose to inflict misery.

We’ve got a long way to go before animals would likely consider us to be good neighbors, but there’s no better time to start repairing the world than today.