Only addition and subtraction were possible. Consider the case of an amoeba. Some would argue that this is how they feel about the process, whether physically or emotionally. This ambiguity is inherent to understanding of many growth processes. A growth in understanding is readily associated with the greater subdivision of a domain of knowledge.
Progressive specialization is the continuing division of areas of expertise.
This multiplies the number of things that are known. In the case of the individual, it is clearly ridiculous to interpret such growth as an unrestricted increase in size, which might then result in some form of giantism if successful. Rather there is the expectationthat after reaching a certain physical size, growth will take other forms, expressed by such phrases as a growth in skills or a growth in maturity. Again a form of division somehow counteracts the simplistic understanding of additive growth. In the case of a community, growth beyond a certain point evokes a need for some form of order.