It should be obvious that we must define core terms so that a reader of our work can understand the argument without needing to first decipher the author's terminology. This goes for all types of writing but is crucial in scholarly texts. Indeed, scholars often use terms with very precise (and sometimes "unusual") meanings, which is a means to discern theoretical relationships that are much more exact and specific (and thus knowledge-generating) than is necessary in everyday conversations.
As scholars, we typically define the terms we use for the purpose of not inviting unintended interpretations and, especially, misunderstandings of the argument made. But it goes well beyond providing a selective dictionary to shield us from innocent (or intended) misreadings and misrepresentations. It is not merely that the terms used need to be explained, but that many of the terms we use refer to concepts that are building blocks for theorizing and, therefore, understanding. Unless they are properly and clearly defined, the theorizing based on them fails.
The meaning of definition in this context is often forgotten. When peer reviewers ask authors to define their "core terms," the issue is not that, for example, the peer reviewer doesn't understand what is meant by opportunity or startup or entrepreneur. Those terms are easily understood in general, but scholarship is about precision.
For example, we may use a term as "old" to refer to someone who is 80 years of age. Nobody will misunderstand this. The same is true for people who are 85 or 78, they too can be easily and without confusion categorized as also "old." The contrast to "young," which we might use to refer to someone who is 18, 22, or 25 years, is also clear. No one would mistake a 25-year-old for "old" or an 80-year-old for "young."
This is sufficient for everyday conversations. In fact, non-scholars often use examples of obvious cases in lieu of definitions of the terms. Asking someone to define what "old" means, they might say "someone who is like 80 years old or more." But this is not a definition and it is entirely unsuitable for scholarship. Why is an 80-year-old "old" whereas a 79-year-old is not?
And why is it that a person at 80 years is old whereas a church or findings in an archeological dig are not? It is also not sufficient to say that it is "relative," because that only raises the question relative to what? An 80-year-old is indeed old compared to a 22-year-old, but so is a 50-year-old. But a 50-year-old is young compared to an 80-year-old. And a 22-year-old might be young also compared to a 25-year-old.
What matters for definitions, which must clarify the meaning, is not what falls within or without - but what constitutes the boundary. If we were to categorize people into old vs. young, where does the 50-year-old fall - in the "old" category together with 80-year-olds or in the "young" category with 22-year-olds? We have to draw the line somewhere, but that line cannot be drawn arbitrarily. In fact, where we draw the line is what makes the definition useful or not.
Definitions of concepts are not about the contrast between what-is or what-is-not, but about what determines the distinction, the basis for making it, and what it divulges in terms of meaning. It is the demarcation that makes the definition, not what cases end up falling on either side of the dividing line.
Getting definitions right is of extreme importance when conceptualizing in social science because the concepts that matter in people's behavior are rarely physical entities with what appears to be "obvious" boundaries. An astronomer typically does not need to spend much time on explaining what demarcates a star from its surrounding space. Similarly, a biologist might not need to elaborate much on where a virus or body begins or ends.
In social science, however, most concepts do not have limits that appear obvious. There is no physical reality to institutions, behavior, values, etc. and therefore also no obvious way to measure where they begin or end. What is an entrepreneurial opportunity and what is not? It is easy to point to Ford's Model T or Apple's iPhone as taking advantage of entrepreneurial opportunities. It is similarly easy to recognize that Elon Musk is an entrepreneur. But where does one draw the line?
Is it an entrepreneurial opportunity to start a new type of restaurant? Maybe. Is it an entrepreneurial opportunity to start a Chinese restaurant to compete with the existing one(s)? Is it an entrepreneurial opportunity to start another Subway or MacDonald's franchise in a town that already has several? Is it an entrepreneurial opportunity to take over an already existing franchise? What examples fall inside vs. outside of the definition? And, more importantly, what knowledge does the demarcation produce?
The point of a definition is not to state a difference that is obvious, but an exercise in figuring out dividing lines. The essence is the dividing line, the demarcation of what-is from what-is-not and, specifically, what we can learn from drawing this line. But it is not a matter of drawing a line at random to see what, if anything, can be learned from it. The difficulty of definitions is to work out an argument for why drawing the line exactly where it is drawn is not only appropriate but also useful and produces new insights.
In other words, definitions in scholarship are not primarily about defending the argument from misunderstandings or misrepresentations. They are tools in theorizing, building blocks for creating new insights that help us understand the world better. Definitions must therefore not only be worked out clearly but be carefully crafted. Defining is in itself an act of scholarship. It should be taken much more seriously.