All people are born with an equal right to freedom. Why are they then under their parents power? Because they are born without reason, the tool that people use to survive in both the state of nature and society. Parental power extends until the child is grown old enough (Locke uses twenty-one as an example age) to function independently within society. Likewise, the commonwealth at this age attributes the responsibilities and duties of an adult to a person who reaches this age of readiness. Thus, reason leads to personal freedom.
Locke's problem here is the equation of monarchical power with paternal power. He starts out by noting that if the phrase were changed to "parental power"--to include the mother in the situation--people would not make the mistake of associating parental power with political power. Locke then notes that political power and paternal power are totally different. People are free of paternal power when they are old enough to function as individuals; but political power is built on wholly different foundations.
Chapter 7 begins with Locke's description of the first society, conjugal society between a man and a woman. Locke then describes conjugal society as separate from political society; in it the master and mistress of the household have power over everyone in that household, although that power is neither absolute (they lack the power of life and death) or political.
Locke reiterates his description of civil society as a united body of individuals under the power of an executive that protects their property and well being, and designs legislation to govern their behavior. Thus the commonwealth combines the legislative power to make laws and the executive power to enforce laws, with the public's support. The difference between this and the paternalistic society, in which people are born into filial obligations that then extend throughout their adulthood, is significant.
Locke ends the chapter with a description of all the ways in which absolute monarchy violates these principles. Absolute monarchy places no common authority over all; thus, by investing the authority in one person, the entire system suffers. Since the monarch can impinge on people's property and welfare without fear of retribution, the people lack the comfort, protection, and incentive to contribute to the good of the commonwealth. To prevent such an imbalance of power, the legislature and executive must be placed in a collective body. Thus, no individual is exempted from or above the laws of the commonwealth.
These two chapters define civil society by describing what it is not--paternal or conjugal society. Why should Locke spend so much time establishing this distinction? In Locke's time, it was very common for political philosophers such as Sir Robert Filmer to compare kings to fathers of their subjects to justify their absolute power. Locke was also aware of the traditional historical notions (Locke uses the Latin term paterfamilias) of the family social unit centered on the father as both the paternal and political center of power