Requirement 2: Ideas must be expressed economically

Living things attempt to use the minimum resources required to achieve their goals.

Look at this table of some human activities:

People are economic with their money, with their time and with their energy: they buy things as cheaply as possible, and they do things as quickly and with as little energy as possible.

But people are also economic with their mental activity. In any act of thought, they wish to expend the minimum mental activity required for understanding. It is easy to quantify the units of money, time and energy as the yen, minute and kilojoule, respectively, but for mental activity we need a new unit - let’s call it 'mental price', charged in 'mental ¥'.

Each idea charges a mental price. As a writer, your job is to minimize it. Some examples will illustrate the point.