An ideal is a principle or cultural value that one actively pursues as a goal. Ideals are particularly important in ethics, as the order in which one places them tends to determine the degree to which one reveals them as real and sincere.
Someone who claims to have an ideal of honesty but is willing to lie to protect a friend is demonstrating that not only does he hold friendship as an ideal, but, it is more important than honesty.
In applied ethics
In some theories of applied ethics, such as that of Rushworth Kidder, there is importance given to such orders as a way to resolve disputes. In law, for instance, a judge is often called on to resolve the balance between the ideal of truth, which would advise hearing out all evidence, and the ideal of fairness, which would require keeping some evidence unfairly gathered or impossible to validate out of the process.
In politics ideals play a pivotal role. During the French Revolution, the principles of "Liberté,_égalité,_fraternité" were raised to the status of ideals. The Ten Key Values of the Green Party are likewise raised to such status today. In fact, most political movements have a certain set of ideals. However, in many cases, one can easily find instances where ideals were "not lived up to" - some of which are cases where one simply proved to outweigh another for some specific decision, or where all were compromised simply to retain the power to continue to pursue them.
Idols and heroes
A different form of ideal is an idol or hero, who is held up as a source of inspiration. Since this is an actual person or fictional character, it is too complex and multi-faceted to be considered an ideal in the abstract sense. However, when they are encountered in the form of a story, with only a few traits on display, they are a simplified archetype from which one can very easily derive stereotypes or mimicry. In Islam, for instance, the life of Muhammad is held up as "ideal", but must be interpreted for believers through the tale of his life, or sira, and his many sayings, the hadith.
Ideal and virtue
Given the complexity of putting ideals into practice, and resolving conflicts between them, it is not uncommon to see them reduced to dogma. One way to avoid this is to have ideals that themselves are descriptive of a process, rather than an outcome. A virtue, in general, is an ideal that one can make a habit.
In formal axiology, Robert S. Hartman contended that being ideal means that something is the best member of the set of all things of that class. For example, the ideal student is the best member of the set of all students in the exact same way that the ideal circle is the best circle that can be imagined of the class of all circles. Since we can define the properties that the ideal member of a class should have, the value of any actual object can be empirically determined by comparing it to the ideal. The closer an object's actual properties match up to the properties of the ideal, the better the object is. For example, a bumpy circle drawn in the sand is not as "good" as a very smooth one drawn with a compass. In the world in general, each particular object ought to become more like it's ideal. In ethics, by analogy, each person should attempt to become more of an ideal person, and a person's morality can actually be measured by examining how close they live up to their ideal self.
The ideal world," says Nietzsche, "is a lie invented to deprive reality of its value, its meaning, its truth. Until now the ideal has been the curse of reality. This lie has so pervaded humanity that it has been perverted and has falsified itself even in its deepest instincts, even to the point where it bows down to values directly opposed to those which formerly ensured progress by ensuring the self-transformation of the present."—Raoul Vaneigem, The Revolution of Everyday Life