Central to Spencer's sociology is the presentation of society as a social organism. Constant attention is paid to the structure, function and growth of the social organism and one discovers frequent reference to the biological analogy of the individual organism in order to illustrate the point. Spencer's fondness for the analogy should not obscure his intention:

‘Though, in foregoing chapters, sundry comparisons of social structures and functions to structures and functions in the human body have been made, they have been made only because structures and functions in the human body furnish familiar illustrations of structures and functions in general. The social organism, discrete instead of concrete, asymmetrical instead of symmetrical, sensitive in all its units instead of having a single sensitive centre, is not comparable to any particular types of individual organism, animal or vegetal.’ 1