My dictionary defines the word tool in some interesting ways. A tool is "an instrument like a hammer, used or worked by hand." A tool is "a means to an end." And—more sardonically—a tool is "someone who is used or manipulated by another; a dupe."

Humans have been making tools for a long time. It's a skill that sets us apart as a species. We use our brains to extend our physical abilities, and we do it all day long. I'm doing it right now, because language itself is a tool. It allows us to understand each other. It also vastly increases our ability to observe, reflect on, and communicate our experience of the world. The Roman alphabet has just twenty-six letters, but we combine those phonetic symbols in millions of ways to express all the nuances of sorrow, joy, love, culture, and genius.

Our human talent with tools makes science and technology possible. Science is simply a disciplined method of getting knowledge about the world. That's what the original Latin word means; scientia means knowledge. And technology is the application of science to solving practical problems like landing on Mars or moving a ton of bricks. The word technology comes from the Greek words techne, which means craft or skill, and tekton, which means carpenter or builder.

So why is any of this important? It's simple. Science and technology are the language that shapes the modern world. And here's what that language has wrought: Researchers have now successfully reprogrammed mature human skin cells back into an embryonic-like state. This is big news on three different levels.

First, it's an achievement that few people could have imagined even thirty years ago. We should give praise for this in the spirit of St. Irenaeus when he said, "God's glory is man fully alive." The accomplishments of humanity reflect the grandeur of our Creator. Second, this kind of breakthrough will have wonderful results for medical research. And third, it's entirely moral. Good people have been arguing for years that adult stem-cell research has huge potential for advancing human health without the need for destroying a single human embryo. They were right. Now the evidence is starting to prove it.

Here's another thing the language of science and technology has wrought.

Most of us naturally focus our attention on scientific advances in medicine, energy, communications, and commerce, because these things touch our daily lives. But the real engine of technological change has always been war, and science is changing the nature and lethality of war at a rapid pace. The United States already has flying drones that killed more than 2,000 Iraqi insurgents in just one year. We now have robotic weapons that can launch by themselves, fly thousands of miles, patrol an area the size of Ohio, then fly back and land themselves. The idea of swarms of semi-intelligent combat drones lingering over a region, and preprogrammed to attack certain kinds of behaviors on the ground, is not science fiction. It's a fact, or it soon will be; and this is only one example of the drastic changes in the conduct of war that are coming in our lifetime. More importantly, America is not alone. Many other countries (and groups, some of them not very friendly) will have the same technologies.

The historian Edward Tenner once warned that every new technology brings with it a "revenge of unintended consequences." We invent cars, for example, to move us more quickly—and of course, they do. But we also end up with traffic jams, oil dependency and pollution. We're never as smart as we think we are. The modern scientific mind likes to imagine itself as Prometheus, the hero of Greek myth who's punished by Zeus for stealing fire from the gods and giving it to humans. But we're really much more like the Sorcerer's Apprentice: smart enough to use the Master's magic, but not smart enough to know where it leads or how to control it. 

Isaac Asimov, the great science fiction writer and biochemist, once said that "science acquires knowledge faster than humanity acquires wisdom." Of course he was right. And that's bad news, because while the tendency to forget our limits as creatures is not new to human history, the cost of our forgetting has gone sharply up. We already have the ability to blow ourselves to radioactive vapor. Very soon we'll have the skills to reprogram who we are at a genetic level and even create new species. We're the first generation in history with the power to change what it means to be "human" at a biological level. And that power comes at exactly the moment when we seem least willing to think morally and modestly about our power.

There's an old saying that goes like this: "To a man with a hammer, every problem begins to look like a nail." That's where we are today as developed societies: Science is reshaping our morality and social thought, when a genuinely sane culture would have it the other way around.

To put it another way: Human beings use tools, but in using them, our tools also use and change us. They shape our choices and channel our perceptions. They modify the way we think, what we think about, and the way we live our lives. But not every human problem can be solved with a hammer. And not every human need or longing can be met by the tools of science or technology, because both lack the vocabulary to respect, or even understand, those qualities about being "human" that are most unique and precious, and can't be materially measured.

The fatal flaw in our developed societies and their idolatry of science—because that's what it is, a form of idolatry and avarice for power—is that their idea of man is too vain and too despairing, too big and too small at the same time. We're less than gods but more than smart monkeys. And the glory God intends for each of us can only be found one way, through one Man.

I've always been struck by the fact that the human stepfather of Jesus was a tekton; a carpenter and builder. So was Jesus himself. Jesus would have known, from a very early age, the feeling of sweat and stone and wood, the sting of splinters in his hands, and the satisfaction of shaping raw material to human need. He would have learned from Joseph real skill at his labor and a respect for the ingenuity of his craft. But he also would have learned the place of his work and his tools in a genuinely human life—that is, a life shaped by prayer, study in the synagogue, love for his family and people, and a reverence for the Torah, the Word of God. He also would have understood the treasure of silence, and Scripture tells us that Jesus sought it out.

Here's the moral of these observations. The next time we hear a public official tutor us about "the rightful place of science" when it comes to conflicts over bioethics, genetics and other sensitive matters of human dignity, we'd do well to examine who—or what—shaped the thinking behind his words, and where his thinking leads.

As Scripture says, "I have set before you life and death, blessing and curse; therefore choose life that you and your descendants may live" (Deut. 30:19). We are the subjects, not the objects, of God's creation. But, of course, we need to believe that and then act like it, and then work to ensure that our culture does the same.

Charles J. Chaput, O.F.M. Cap., is archbishop of Denver and author of Render Unto Caesar: Serving the Nation by Living Our Catholic Beliefs in Political Life.