It is one of the oldest and most popular theories of the State. It was propounded by ancient philosophers, medieval writers and modem thinkers. For instance, Plato compared the State to human individual and said that the best-ordered commonwealth was one whose structural organisation resembled most nearly in principle to that of the individual”.
In modem times, many thinkers regard the State as an organism. The Swiss writer Bluntschli asserts that the State is the very “image of the human organism”, and even personifies the State as masculine in character. There is, however, one difference between the ancients and the modems.
The former believed that the State resembled an organism, while the latter assert that the State is an organism. From an analogy or comparison between human society and State with living organism, it became a fashion in modem times to identify the two as one and the same kind of organisms. The result was that Political Science was made a branch of natural sciences, especially of biology, instead of being a branch of social sciences.