TABLE OF CONTENTS This chapter defines key systems concepts and discusses the associated ideas of the P/p methodology.
Some people dismiss constructing or quoting definitions as a futile academic exercises in semantics , or waste of time because we all know what we mean . Such remarks amount to excuses for laziness of the mind: reluctance to think deeply and express ideas clearly.
The purpose of a definition is to explain the precise nature of a thing and state it clearly, so that a platform of common understanding may be established between communicating parties. Defining terms is an obligation towards oneself, and a matter of courtesy towards one's co-communicator. Definitions are helpful in everyday life, but they are essential in professional practice to avoid misunderstandings and errors.
To be fit for both professional and general purposes, definitions should be meaningful and informative. They must be:
traceable to the concept they elucidate,
grounded; state the meaning in widely used words given in general purpose dictionaries, or express it in terms already defined,
affirmative rather than negative (stating what something is, rather than what it is not),
free of vagueness (exclude doubtful borderline cases),
free of ambiguity (avoid the use of the same term for designating two or more concepts),
free of circularity (if A is defined in terms of B and B in terms of A then nothing is defined),
free of recursion (if A is defined in terms of A itself then...
