D.1. Non-Economics:
If Economics is the scientific study of that aspect of human behaviour which comes out of conflict between multiple ends, and scarce but substitutable means
it follows
If it is not the case that a study is “the scientific study of that aspect of human behaviour which comes out of conflict between multiple ends, and scarce but substitutable means”, it is not Economics .
Note: The implications of 'it is not the case that a study is “.. .. .. ..” can be obtained by negation of each component of the definition within “.. .. .. ..”.
E.1. Let a simpler expression for such an aspect of behaviour which is triggered due to multiple but scarce and substitutable means against multiple ends be "Choice Making".
E.2. The implications of 'it is not the case that a study is “..............”:
D.2. Absence of Ends: Our habits, or our nature etc is not choice making, and thus not focus of economics.
D.3. Absence of Multiple Ends: If there is one end, and one end alone, then it is not a matter of choice making, does not require compromising, and thus not focus of economics.
D.4. Absence of Focus on Aspect of Behaviour: To study a category of behaviour instead of an aspect in general, such as buying or selling, is to reduce to scope of study of choice making, and thus not economics but only a part of it.
E.3: We make choices in all spheres of life from matrimonial to business, from lab science to politics. Everywhere we engage in Choice Making, thus to narrow scope to only buying and selling in physical market is not desirable.
D.5. Absence of Multiple Means: If there is only one mean at our disposal, it is not choice making at all, and thus not focus of economics.
D.6. Absence of Scarcity: Any instance of sufficiency implies we need not to make sacrifices, or to make choices, and thus not focus of economics.
D.7. Absence of Substitutable Means: If we cannot substitute our means for one another, cannot exchange or postpone, it is not choice making, it does not establish a market, and thus not focus of economics.
D.8. Absence of Scientific Study: If it is not scientific study of choice making, it is not economics.
E.4. If it is motivated by ethical grounds, it can be an application of results of economics to acquire certain ends. But science of economics is equally interested in study of the implications of ethical values deemed undesirable at the moment.