According to Locke, political power is the natural power of each man collectively given up into the hands of a designated body. The setting up of government is much less important, Locke thinks, than this original social–political “compact.” A community surrenders some degree of its natural rights in favor of government, which is better able to protect those rights than any man could alone. Because government exists solely for the well-being of the community, any government that breaks the compact can and should be replaced. The community has a moral obligation to revolt against or otherwise replace any government that forgets that it exists only for the people’s benefit. Locke felt it was important to closely examine public institutions and be clear about what functions were legitimate and what areas of life were inappropriate for those institutions to participate in or exert influence over. He also believed that determining the proper role of government would allow humans to flourish as individuals and as societies, both materially and spiritually. Because God gave man the ability to reason, the freedom that a properly executed government provides for humans amounts to the fulfillment of the divine purpose for humanity. For Locke, the moral order of natural law is permanent and self-perpetuating. Governments are only factors contributing to that moral order.

For Locke, all knowledge comes exclusively through experience. He argues that at birth the mind is a tabula rasa, or blank slate, that humans fill with ideas as they experience the world through the five senses. Locke defines knowledge as the connection and agreement, or disagreement and repugnancy, of the ideas humans form. From this definition it follows that our knowledge does not extend beyond the scope of human ideas. In fact, it would mean that our knowledge is even narrower than this description implies, because the connection between most simple human ideas is unknown. Because ideas are limited by experience, and we cannot possibly experience everything that exists in the world, our knowledge is further compromised. However, Locke asserts that though our knowledge is necessarily limited in these ways, we can still be certain of some things. For example, we have an intuitive and immediate knowledge of our own existence, even if we are ignorant of the metaphysical essence of our souls. We also have a demonstrative knowledge of God’s existence, though our understanding cannot fully comprehend who or what he is. We know other things through sensation. We know that our ideas correspond to external realities because the mind cannot invent such things without experience. A blind man, for example, would not be able to form a concept of color. Therefore, those of us who have sight can reason that since we do perceive colors, they must exist.

Locke argues that God gave us our capacity for reason to aid us in the search for truth. As God’s creations, we know that we must preserve ourselves. To help us, God created in us a natural aversion to misery and a desire for happiness, so we avoid things that cause us pain and seek out pleasure instead. We can reason that since we are all equally God’s children, God must want everyone to be happy. If one person makes another unhappy by causing him pain, that person has rejected God’s will. Therefore, each person has a duty to preserve other people as well as himself. Recognizing the responsibility to preserve the rights of all humankind naturally leads to tolerance, the notion that forms the basis for Locke’s belief in the separation of church and state. If we all must come to discover the truth through reason, then no one man is naturally better able to discover truth than any other man. For this reason, political leaders do not have the right to impose beliefs on the people. Because everything we understand comes through experience and is translated by reason, no outside force can make us understand something in conflict with our own ideas. Locke insists that if men were to follow the government blindly, they would be surrendering their own reason and thus violating God’s law, or natural law.

The right to private property is the cornerstone of Locke’s political theory, encapsulating how each man relates to God and to other men. Locke explains that man originally exists in a state of nature in which he need answer only to the laws of nature. In this state of nature, men are free to do as they please, so long as they preserve peace and preserve mankind in general. Because they have a right to self-preservation, it follows that they have the right to those things that will help them to survive and be happy. God has provided us with all the materials we need to pursue those ends, but these natural resources are useless until men apply their efforts to them. For example, a field is useless until it produces food, and no field will produce food until someone farms it.

Locke proposes that because all men own their bodies completely, any product of their physical labor also belongs to them. Thus, when a man works on some good or material, he becomes the owner of that good or material. The man who farms the land and has produced food owns the land and the food that his labor created. The only restriction to private property is that, because God wants all his children to be happy, no man can take possession of something if he harms another in doing so. He cannot take possession of more than he can use, for example, because he would then be wasting materials that might otherwise be used by another person. Unfortunately, the world is afflicted by immoral men who violate these natural laws. By coming together in the social–political compact of a community that can create and enforce laws, men are guaranteed better protection of their property and other freedoms.