Here I relate what I perceive to be the most important points of Bertalanffy’s General Systems Theory, a copy of which I was given by a professor in the department when he moved to a smaller office and had to purge his bookshelves. 
Most generally, the idea behind General System Theory is that there are (or at least appear to be) mathematical rules which are stable and can be applied across many levels of organization (e.g., cell, organism, society).
For instance, the second law of thermodynamics (diffusion) makes reasonably accurate predictions of both people and animals in space and the diffusion of ideas throughout a population. The similarities between different levels (e.g., cellular, organismic, societal) are called isomorphisms, and the entirety of the theory is an attempt to combine different fields of science into a more coherent whole. Throughout Bertalanffy’s own intellectual development, he reports noticing the striking similarities (which are now common knowledge, this was published in 1968) between differential fields such as Physics, Chemistry, Biology, and other fields like Psychology, Sociology, and Economics.
The essense is that many of the ideas in these fields rely upon similar mathematical underpinnings. General Systems Theory is then an attempt to apply mathematics across fields like Chemistry, Biology, Psychology, and Sociology in order to create a more unified science.
An example of this sort of thinking is the, ‘law of natural growth’ which is basically a mathematical statement about exponential growth. This law can be applied, at the same time, to the growth of capital through compound interest, the growth of baceria, the growth of peoples and ideas, and even the growth of scientific theories. Conversely, the same law in reverse can be applied to radioactive decay, the decomposition of some chemicals, the destruction of bacteria by poisin, loss of weight through hunger in multicellular organisms and the of decrease of populations.
The law of exponential growth, which can be utilized to explain diverse phenomenon.
This is but one example, others deal with competition, for instance within the individual in the weight of their organs or their percieved value of ideas. Eithin sociology, this equation is generally referred to as Pareto’s law, which describes the distribution of income relative to the overall growth of the system. Competition between individuals in all aspects of life, and even competition between species can be described using this general formulation.
The essential of systems theory, many levels of organization, building upon eachother, across which similar mathematical models can be utilized for explanation.
The final major concept we will cover here is that of unity, or those cases where the total is more than the sum of its parts. Specifically, it is a process of specialization that allows this. The more complex the system, the less replaceable each part becomes as each piece becomes less general in its function. Thus, the stomach cannot be replaced with an extra lung. This is the cell, with its individual parts, the organism of many cells, the group of many organisms. This levels thinking is the real value in General Systems Theory and has led to a greater integration between the different sciences. As Bertalanffy said, “Modern science is characterized by its ever-increasing specialization, necessitated by the enormous amount of data, the complexity of techniques and of theoretical structures within every field. Thus science is split into innumerable disciplines continually generating new subdisciplines. In consequence, the physicist, the biologist, the psychologist and the social scientist are, so to speak, encapusulated in their private universes, and it is difficult to get word from one cocoon to the other…”
The key to General Systems Theory is to look across fields to examine the isomorphisms, how they are similar, in order to arrive at a more cogent understanding of reality.
This has been a brief introduction to the essentials of systems theory, leave your comment below and suggest the next theory to be summarized. 🙂
Psychology things 