Patriotism is a feeling of love and devotion to one's own homeland (patria, the land of one's fathers). This article surveys the concept of patriotism from the viewpoints of history, politics, ethics, and biology.

Different people have different opinions about whether patriotism is morally good. Often, these opinions vary according to what sort of patriotism is involved.

Some instances of patriotism induce almost universal admiration. To give just one of many possible examples, in 1940, a number of Dutch soldiers gave their lives in a hopeless cause attempting to defend the Netherlands from invading Nazi armies. This act would be considered by almost everyone to be a clear case of selfless, admirable patriotism.

Yet many of the invading Nazi soldiers doubtless felt, too, that they were engaged in a patriotic act, in this case on behalf of the German nation. Many of them had been indoctrinated in a form of unquestioning patriotism during their teenage years, while they were members of the Hitler Youth. Very few people today, even in Germany, would consider the unprovoked German attack on Holland to have been justified, and to the extent that patriotism facilitated it, then patriotism could be considered, in this case, a bad thing. Throughout history, various governments have invoked patriotic feelings to support military aggression, arbitrary imprisonment of aliens, and even murder, acts considered evil by most individuals.

In addition, many politicians have exploited patriotism in attacking their opponents, accusing them of betraying the nation. In the view of many, the nature of these comments harm political discussion and provide less opportunity for deliberative democracy to flourish, because it appeals only to a visceral negative emotion (that is, angry patriotism), rather than to voters reasoned views on policy.

Many believe that the surge in patriotism enabled a number of major changes in national policy. The (significantly named) USA PATRIOT Act, which was signed into law on October 26, 2001, was designed to combat terrorism but is considered by many to constitute a harmful assault on civil liberties. It is also possible that the patriotic surge created a political climate under which it was possible for the Bush Administration to launch wars first in Afghanistan and then (far more controversially) in Iraq.

Like almost all wars, the wars in Afghanistan and Iraq appear to have increased patriotic feeling. As casualties have mounted and opposition to the war has increased, a pattern seen earlier in the Vietnam War has reemerged: those in favor of war consider that those who oppose it are unpatriotic, or even outright traitors. Several conservative commentators have indicated they feel that news that paints the US in a negative light is giving aid and comfort to the enemy. Since war opponents understandably resent such accusations, the political debate has taken place in an atmosphere of increasing anger.