Functional Theory: Functional theory is a perspective that maintains that a society as a whole is a sum of its parts; that each part is functioning in a manner conducive towards the stability of the society at large. These parts can best be described as being various institutions within a stable society such as government, school and universities, healthcare, etc. It has its origins in the works of Emile Durkheim.
Symbolic Interactionism: As the name suggests, symbolic interactionism as a perspective in sociology, is the interaction and analysis between various members of a society with the help of specific symbols. These symbols could hold more than one meaning and could even be represented by language. Symbolic Interactionism originated with George Herbert Mead and Charles Horton Cooley.
An issue of grave concern that we as a society at large are facing today is unemployment. A conflict theorist might, for example, chalk it up to differences in social and economic conditions between an employed and an unemployed individual. He can also mention lack of equal treatment and/or opportunities due to differences in their race, religion, gender, location, etc. On the other hand, a functional theorist might be quick to blame the local political and educational institutions within the domain of the unemployed individual as having contributed towards his unemployment by not functioning at their optimum capacity and, thereby, causing him to have garnered less skills and talent, which led to his current, sorry state.
A proponent of symbolic interactionism might present a third perspective for the issue of unemployment. He might argue that lack of proper instruction during early childhood, both from the end of the parents, as well as, the teachers may have led to this unemployed individuals current predicament by not motivating him enough and not developing a strong enough set of skills for him to retain and maintain employment as a grown-up.