Difference between General Systems Theory and Systems Theory are as follows:
While General Systems Theory is applicable to all systems, the Systems Theory is applicable only to political systems and can be applied to Political Science.
There is a system at all levels. For example in cosmos there is a solar system.
On earth there are systems of weathers. In society there are social, political, economic and cultural systems. In the human body also there are digestive, circulatory and nervous systems. In cars, scooters and buses etc. there is a mechanical system.
In the family there is a social system where all the members work for the welfare of the family. So the General Systems Theory applies to all systems while the Systems Theory is applicable only to political system.
Almond defines political system as “that system of interaction to be found in independent societies which perform the functions of integration and adaptation (both internally and vis-a-vis other societies) by means of employment of, more or less, legitimate physical compulsion.
It means that:
(a) A political system is a concrete one which influences and is influenced by environments. It uses legitimate force as a last resort.
(b) Interactions take place not between individuals but between roles; and
(c) The political system is an open system in the sense that it is engaged in continuous communication with system or entities outside its own boundaries.
This definition also ascribes three characteristics to a political system-comprehensiveness, interdependence, and existence of boundaries which have been already explained in detail. Then another difference between the two is that in General Systems Theory there is lack of explanation because it tries to give proper consideration to all systems, where as Systems Theory can be subjected to more explanations.
According to Oven Young Systems Theory developed out of General Systems Theory whereas J. Spiro does not agree with this view. According to him Systems Theory has been in use in Political Science for quite a long time.
General Systems Theory has its own advantages and limitations. It main advantage is that it has helped in the analytical study of the systems but the theory “as its serious limitations as well. It lacks capacity of explanation. Secondly, the theory fails to understand such serious problems as power, influence and policy formulation.
Consequently, the theory has not been able to show its impact in the political field but its idea of feed-back has become quite popular: Therefore David Easton is of the view that in spite of its limitations, the theory has quite a bright future.