The moral obligation of consent breaks down when a government fails to protect, or worse causes harm, to those it is supposed to be governing. Since Locke says that when a people consent to government, the ``great and chief end ... is the preservation of their property, '' it becomes necessary to dissolve government and create it anew if it fails in that respect (66). If a leader or ruler is engaging in acts which would take power beyond that which has been given to the government, Locke says that this person is no longer acting as a ruler and ``may be opposed, as any other man'' (103).
Part of the reason government is created is to act as judge in disputes. When there is a dispute with their government, however, there is no higher authority to serve in the judicial capacity. Locke realizes that man should not be the judge of its own case, and yet there is no higher earthly authority. In this case Locke says that the people ``have a liberty to appeal to heaven'' (87). God will then be the judge in their plea.
Locke's theory of the right to rebel centers around the fundamental law of nature, which says that preservation of one's life is to be valued above all else. Therefore, if a government takes actions that would impinge on one's fundamental duty to preserve life, one has no choice but to act against that government and rebel. The duty to obey the fundamental law is a duty to God, and one that no man has the right to give away. Therefore rebellion is not only morally justified, but morally justified under the highest possible reason.
Practically, rebellion against the government is not always the most prudent course of action. If those whose rights are being taken comprise a large minority, or are even just a few, it may well be that it is impossible for them to attempt resistance. Though they have the right to resist, the right ``will not easily engage them in a contest, wherein they are sure to perish'' (105-106).
Though Locke justifies rebellion against a government that infringes upon the rights of the governed, he seldom justifies the use of violence in this rebellion. Locke feels that violence is only a valid response to violence, and that all other disputes must be worked out through civil means. ``Force is to be opposed to nothing,'' Locke states, ``but to unjust and unlawful force; whoever makes any opposition in any other case, draws on himself a just condemnation both from God and man'' (103).
Locke realizes that every government has the ability to become corrupt, and that any model for the justification of government must include a method for those wronged by government to regain a state of peace. Therefore, Locke has no choice but to acknowledge the right of the governed to rebel when the government fails to protect the interests of those it represents or attempts to wrongly usurp power it does not possess.