A language is a convention according to which certan material objects, to be referred to as linguistic objects , define certain actions , which are referred to as their meanings . Commands are used in the context of control , where the meaning of a command issued by the controlling system is the resulting action of the controled system.
Human language is a multilevel system.
In our theories we construct higher levels of language. Predictions produced by the higher levels are formulated in terms of the lower levels. It is a hierarchical system, where the top cannot exist without the bottom. This is a very imprecise terminology because abstraction alone is not sufficient to create high level concepts. This intermediate linguistic level of numbers must become reality before we use abstraction on the next level.