The first comment was on the question of how we define the key term of medium, and in it I try to make a serious point in a lighthearted way:
The sky is the medium for birds, hot air balloons, airplanes, and missiles. It's the medium of flight, and projectiles.
A stone can be a medium of conflict, just ask Goliath, or a medium for statues and monuments.
The book is a medium for storing writing. Writing is a medium for recording the spoken word in a visual, non-ephemeral form. Speech is a medium for expression, interaction, influence, transmission, and thought based on the code of language. Language is a medium for transforming the chaos of the perceived world into a verbal map that provides the illusion of stability, coherence, predictability, and abstraction.
This discussion list is a medium for the interchange of comments that range from the ridiculous to the sublime.
The following, more extended commentary was a specific response that draws on general semantics, in particular the need for operational definitions, in discussing the way that scholars and researchers proceed to set up their studies:
You should understand that definitions of key terms ought to be presented as operational definitions, meaning that they are put forth as definitions "for the purposes of this study." This doesn't mean that you can attach any random definition to any particular term, there still has to be support for it, but it does mean that the definitions you do wind up using cannot and should not be applied to uses of the terms outside of your study. That is to say, you cannot define your terms a certain way, and then act as if others using the term are using the same definitions as you are, ignoring the differences. And you cannot simply act as if others who do not use your definitions are using the wrong definitions. To do so, to ignore or forget that the definitions you put forth are your own creation and not some natural or essential quality of the phenomenon in question, and that makes you guilty of reification, which is exactly what you are doing, reifying your definition of "medium" (Neil Postman would call this either crazy talk or stupid talk, or maybe both).
Moreover, the propaganda technique of persuasive definition involves putting forth your own definition as the only possible definition. While I don't think your intention is to propagandize in the typical sense, you are trying to force your definition on the rest of us by asserting and insisting that it is the only correct way to understand the term. In this sense, you are acting as a propagandist for your views. This goes against the norms of acceptable scholarship.
Just to give a few counterexamples, let's take Harold Innis, who distinguishes between heavy and light media. In his work, the clay tablets used to record Sumerian cuneiform are a heavy medium. The papyrus sheets and scrolls used to record Egyptian hieroglyphics are a light medium. Or let's consider how artists refer to the materials they use as their medium, e.g., oil paints on canvas, charcoal on paper, carvings from wood, busts chiseled from marble, etc. Or how Edward Sapir referred to language as the medium for literature, and how different languages constitute different media. Or how Edmund Carpenter likewise stated that every language is a mass medium. Or how McLuhan argued that a medium is any extension of the human body, and thereby including all forms of technology and human invention and innovation. Or how Postman in his keynote address to the first MEA convention said that a medium is a technology within which a culture grows. Indeed, Joshua Meyrowitz has written several essays about the differences between definitions of "medium" that view the concept as a form of transportation or conduit, as a language, and as an environment.
As for your distinction between philosophical and practical discussions, I think there are many who would take issue with the idea that practical discussions are devoid of any philosophical basis, and maybe even that philosophical discussions are devoid of any practical value. In any event, to just assert that your definition is more practical is a meaningless statement, because the question is, practical for what? For what purpose? To what end? This brings us back to operationalism. Your definition may be more narrow, more limited, than other definitions, but that alone does not prove that it has greater utility. By that logic, defining "medium" as a device powered by electricity that enables two people to speak to one another would be even narrower and more specific, and therefore more "practical" in your sense of the word, but it would not be a definition that would be considered particularly well formed or useful within the community of media ecology scholars, and by most outside of our community as well.
And I provided one more set of comments in response to some discussion on the distinction between "natural" and "artificial" in regard to media:
I understand the "natural" tendency to make this distinction, which seems clear enough at first glance. But, as you no doubt know, the artificial-natural dichotomy is often invoked in criticisms of technology and innovation, usually unfairly.
For my part, I find the distinction breaks down when we start to look at it closely within the field of media ecology. We know that McLuhan argued that the concept of "nature" was a product of the literate visualism of ancient Greece, and involved placing ourselves as human beings outside of nature, and in opposition to it. Oral cultures did not share this view, and McLuhan pointed to the emergence of the ecology movement as evidence that we were returning to a worldview closer to that of acoustic space in the electronic media environment.
The distinction particularly breaks down in regard to speech and language, which we understand to be "natural" and not a product of deliberate human invention, but falling within the category of media, at least for most media ecologists. To use another example, if I pick up a stone and throw it at you, I have not created or altered the "device" in any way, but I am using it as a medium, and arguable one that is very much interactive.
Then there is the phenomena that Lewis Mumford and Edward T. Hall point to of animal technology. We view nests and hives as "natural" but they certainly are "devices" created as means to certain ends by the birds and the bees, and even if you restrict your definition to media of communication, the point would hold because communication is one of the functions of nests and hives.
We may call animal behavior instinctive, but our capacity for symbolic communication is also inborn, and has been referred to as the language instinct. And I would suggest that we also have a technology instinct.
We also distinguish between natural and artificial selection in discussions of evolution, but doesn't that place us outside of nature, rather than seeing our own impact on the environment as part of the system, not separate from it? Isn't evolution one of the "natural" processes of the universe, whether it occurs within the formation of galaxies and stars, or species, or societies and cultures, or languages and technologies?
Of course, these last questions are rhetorical, the answer, at least in my mind, being yes. And you may not agree with what I have to say here, but whether you agree with me or not come down to a matter of definition, does it not?