What does the 'pursuit of happiness' mean in the Declaration of Independence?

When Thomas Jefferson was asked to write the Declaration of Independence in late June 1776, he did so in just a few days. The document we know isn't terribly long, but the draft he delivered to the Second Continental Congress was much longer, and the original draft was heavily edited, revised and diluted by committee. One phrase that was in both the original and final versions is, "Life, Liberty and the pursuit of Happiness."

Why did this phrase appear in both versions? Jefferson was a well-read person; his home Monticello was filled with the works of contemporary and historic philosophers. In fact, one of Jefferson's favorite thinkers was English philosopher John Locke. Locke originally posited (in "Two Treatises on Government") the idea that a person's right to live a healthy life, free to amass and maintain property -- "life, health, liberty and property" -- is one granted by God. Locke also reasoned that our fates are determined by God; no other individual may interfere with that fate [source: Stanford].

You'll notice that Locke doesn't mention happiness. Instead, he cites property as a natural right. Clearly, Jefferson took Locke's concept of the right to life and liberty and applied it to the fledgling United States and its citizens in the Declaration of Independence. But where did the "happiness" part come from? No one's certain; Jefferson never said. As such, the addition is often attributed to him directly. He was not, however, the first person to use the phrase.

Interestingly, the phrase "pursuit of happiness" was also used by a contemporary of Jefferson's, a British political observer named Dr. Samuel Johnson. Johnson was a Tory, which meant that his sympathies in the struggle between Great Britain and the American colonies lay with the crown. Ironically, he used "pursuit of happiness" in "The False Alarm," a 1770 essay decrying the growing unrest in the colonies that would later give rise to the Continental Congress that produced the Declaration.

It's more likely that Jefferson took the phrase from Locke, argues literary scholar Carol Hamilton, since Jefferson would likely have disdained Johnson's Tory leanings. In 1690, Locke wrote, "The necessity of pursuing happiness is the foundation of liberty" [source: Hamilton]. In the essay, Locke also uses the exact phrase "pursuit of happiness."

Whether it was Locke, Johnson or Jefferson who originally put the idea to paper, precisely what happiness means and how it's pursued in America has long been subject to interpretation.

If there's one thing that can be said about happiness, it's that it's wholly and utterly subjective. What makes one person happy -- picking flowers on a sunny day, perhaps -- may make another person decidedly unhappy. John Locke, however, believed that happiness is the natural state of humanity. As Locke wrote on the subject, humans "are drawn by the forces of pleasure and repulsed by pain" [source: McMahon].

Exactly what gives that pleasure, again, varies widely. Researchers believe that the accumulation of wealth is a major source of pleasure for Americans. For instance, a January 2007 Gallup poll showed that 72 percent of people who made $75,000 a year or more said they were happy [source: WebMD]. Material gain in the forms of money, property and personal possessions isn't the only way Americans pursue happiness, however. In the same poll, people who were married -- no matter what their income level was -- were happier than single people.

Things like new cars, large houses and extensive portfolios, along with having a family and friends make us happy to varying degrees. It's up to the individual, as far as Jefferson was concerned, to determine what makes him or her happy [source: McMahon]. The pursuit part, however, is a different story.

Because happiness was widely considered a natural state for humans in the Jeffersonian era, it was believed to be what God intended and therefore deserved protection. The word's proximity to two other natural rights -- liberty and life -- demonstrates that Jefferson found happiness just as important. The legal and social frameworks provided by the Declaration and the Constitution are meant to create that protection. If a large house makes you happy, for example, then another person shouldn't be able to set it on fire; there are laws against that. What's more, an individual shouldn't legally be kept from pursuing that large house.

When he wrote the Declaration of Independence, Thomas Jefferson avoided defining happiness, choosing to leave it to the individual to determine his or her own meaning of the word. He also may have realized that it's not enough to want to be happy: The path to happiness must be unobstructed, as long as it doesn't interfere with another's happiness, of course.