It is absolutely essential to establish the meaning of the terms being used in a scientific discussion. Scientific terminology is usually precise and often carries meaning somewhat different from that of everyday language. Without agreement on the definition of key terms there is a high likelihood that people will "talk past" one another.

In the specific case of ATM discussions I have seen many instances in which the ATM proponent used what appeared to be standard terminology, but was not. This leads to tremendous difficulty in communication.

Most serious are non-standard uses of scientific terms, combined with the application of those concepts in standard mathematical models -- essentially using the usual theories completely incorrectly. One instance leaps to mind in which an ATM proponent used the term "current", meant something totally different from the usual meaning in science and engineering, and the proceeded to use that non-standard notion in Maxwell's equations in the usual way. The result was a total distortion of the notion of magnetic fields and the importance of those fields in plasma physics.

The insistence on clarity of definition is essential to a meaningful discussion. Moreover it often provides clear and definitive information as to the deficiencies in an ATM proponents claims and in his understanding of basic science. The protestations that Nereid quoted serve primarily to highlight shortcomings in the understanding of the ATM proponents making them.

Lack of understanding of fundamental terms demonstrates lack of understanding of the mainstream theory being challenged. One simply cannot effectively challenge a theory that one does not understand.