In book of THE POLITICS,  Aristotle asserted that man political by nature.  It is this nature of socialization that differs the defference between us human beings and the animals.  Thus, I could not agree more with the assertion that people's behaviors is largely determined by forces not of their own, which clarify the relationship between man and the society.
     A society consists of groups of human beings who are linked together by means of specific costomers and systems, rites and laws and have a collective social existence.  As man is social by nature as Atistotle asserted, a individual is a basic element which composes a society, society is not only likely to 'beyond ourselves ' but to 'in ourselves', society affects us, and vice versa.  Every person is with a clear imprint of the life of the society that helps us to form our personality, so how we act, think, and feel derives from the society that we live in. This kind of currency is a power we are not possible to overthrow, meanwhile, that shapes us by provding moral disiplines which guide our behaviors and controls us desires.
     Laws is a symbol that a force regulates our behaviors, since we are social citizens, we stucture the society, from which helps society cooperates as a whole.  Why do we need laws, and what laws can do for a society?  Human being needs some external limits because we are creatures who are able to want more and more, we are in dangers of being overpowered by our own desires.  The satisfactions are endless, which recepts stimulations but not fills the demands.  Laws are references to social rules, which helps social controlling, social order, disputing settlements and social changes.  Just as people have this or that flaws, we need laws as criteria to dominate undesiable needs when making decisions. 
     Whether people have the ability to make decisions without considering the influence of external environment?  I am afraid not. It is more and more obvious that a individual's character is conditioned by the diversity of his links with the social whole, the degree to which various spheres of life of society have assimilated and refracted in his conciousness and activity.  That contains many sorts of things such as popular minds, career rules and local customs and cultures.  For instance, when you are invited by a Chinese people,  a clock is not excepted as a present, if you do so, the host will feel offensive. Even though you think that is a delicaite present, but it is actually not as suitable as you considered. There is a taboo that clock has the same meaning of death in Chinese, so that we are usually not take it as a present in China.
     People's behavior are determined by both internal factors and external factors, characteristics, family influnce, public minds, regional culture may play important roles in forming people's behavior. It is irrational to overlook internal factors, let alone the externals. Conclusively, I reiterate the notion that People's behavior is largely determined by forces not of their own making.