Why do we categorize photographs the way we do? How did we settle on classifications like still-life and landscape photos rather than dark vs. light photos, or photos of man-made vs. natural things, or photos taken vertically vs. horizontally? Clearly the compositional differences when working in a vertical frame vs. a horizontal one are as profound as the difference between shooting a mountain or a building. But the later crosses a genre line and the former doesn't.
Traditionally the above pairs of photos would fall into different genres, but from the perspective of what is important to me in a photograph the similarities outweigh the differences. This isn't to say the traditional genres are wrong in any sense, just insufficient, and based on arbitrary and often non-useful characteristics.
Questions of genre quickly lead to the more general problems of categorization, which, although going back to Aristotle, remained fairly unexplored until the 50s when philosophers and psychologists found fertile ground in questioning the assumptions inherited from classical theory. The problem of really pinning down categories was neatly summed up by Wittgenstein in 1953: "Categories tend to possess members that have features that are neither necessary nor sufficient." The canonical example is a dog, which despite being described as a barking, four-legged, hairy creature, is still recognized as a dog when it only has three legs or when it doesn't bark or even when it is mostly hairless.
This turns out to be a very interesting problem with deep implications in the way we understand the world. The problems are also relevant to the business of creative professionals because genre is embodied in the idea of specialization and we are often warned of the dangers of not specializing and marketing to a niche—are you a jazz musician or classical musician? a food photographer or architecture photographer? The implications of these kind of questions are that you can't do both well, but since few ever question how these categories came into being, we are never told why. At the moment, though, I am somewhat outclassed by my subject matter and although, this being a blog, that shouldn't stop me from writing at length, I am going to file away criticism of genre and it's relationship to categories as something to be explored more often on these pages and leave with a quote from George Lakoff on why the importance of this subject goes far beyond simple artistic genres.
To change the very concept of a category is to change not only our concept of the mind, but also our understanding of the world. Categories are categories of things. Since we understand the world not only in terms of individual things but also in terms of categories of things, we tend to attribute a real existence to those categories. We have categories for biological species, physical substances, artifacts, colors, kinsmen, and emotions and even categories of sentences, words, and meanings. We have categories for everything we can think about. To change the concept of category itself is to change our understanding of the world. At stake is our understanding of everything from what a biological species is to what a word is.
— Women, Fire, and Dangerous Things