6. In the opposite process of Dissolution or Extinction the thing undergoes the same changes in the reverse order before it disappears as such.
In other words, given a thing and its environment, the one has to adapt and adjust itself to the other, or cease to exist. Nothing survives, as an individual, which does not change. Like a picture in its setting, a thing has to fit itself to its environment in order that it might survive for the best advantage of itself and its kind. Thus, the fit lives and the unfit dies[81]. As the Qur'an expresses it ان الارض ير "the Earth is inherited by only the fit among My creatures."[82] This applies not only to plants and animals, man and society, but also to inanimate or inorganic things, as the President of the British Association announced some years ago.
A man, for example, has for his environment, the atmosphere of the place he inhabits, the society he lives in, the occupation he follows, the laws he obeys, etc. He can live long and happily only when the qualities of his body and mind befit him to that environment, i.e., when they enable him (to become صا لح) to adapt himself continuously to the circumstances of his position. What, then, is the general nature of such qualities?
You know that one of the best methods of Science is Measurement. No scientific knowledge is exact unless it enables you not only to distinguish one quality from another, but also to measure each quality or determine its degrees in some way or other. It is not sufficient to know hot from cold but the degrees of temperature must be measured by a thermometer.
The new methods of Statistics and graphic representation have been applied to a large number of men and women for the purpose of finding "the fittest" qualities or "characters" as they are technically called. Professor Karl Pearson[83] and others have thus found that among a large number of men and women in a given community any physical or mental character which deviates largely, by excess or defect, from the mean or average, renders them the less fit to survive the struggle for existence. Individuals possessing any character which deviates extremely from the mean tend to disappear. For example, the average height of men has been found by measurement of a large number of people to be (say) 5ft. 6in. and it has also been found by statistical methods that men who are 7ft. or men who are only 3ft. are very rare. It is therefore concluded that men who are too tall or too short i.e., who deviate extremely from the mean, tend to disappear and are therefore unfit to survive.
This is only a rough and ready example of what is called the Law of Periodic Selection which has now superseded the Belgian philosopher's Law of the Average (or "the Mean"). It applies to human conduct as well as to human qualities. That conduct alone (i.e., only that particular course of deliberate action) befits a man to his environment, which deviates the least from a standard or average of such conduct. It is the indispensable condition of his happiness and longevity.
You thus see that the Islamic Maxim of the Mean is justified by Science.
Note 12.