I mentioned that I would discuss poorly written stories in order to discover what makes stories good or bad. One of these is the Mary Sue. There are a number of definitions of Mary Sue (and Gary Stu). A Mary Sue may refer to a self-insert character, an overly idealistic character, an author avatar or many other options. For the purpose of this discussion, I stipulate that Mary Sue (or Gary Stu) are limited to characters that are problematic in some way by definition. I will also stipulate that Mary Sues will include all characters under the common usage of that term that happen to be negative – whether by definition or otherwise. (This includes characters that are male in addition to those that are female.) Mary Sues are those characters that have traits (whether accidentally or essentially) that are too good for the genre and those traits draw the readers attention to the character.
There are some definitions of Mary Sues that are not always negative. A self-insert character is not necessarily negative. It is at least theoretically possible for a self-insert character to be a realistic character in a story, avoid breaking the suspension of disbelief and be as essentially unproblematic as any other character. Author avatars can also be realistic characters, for much the same reasons as self-insert characters. Original characters (in a work of fan fiction) can also be done well, even as a protagonist. There are even some definitions of Mary Sue that are even less negative: a protagonist that you do not like, a cliche character or a character that is alien to the original setting in some way.
A Mary Sue could be an overly idealistic character. It is important to note that an overly idealistic character in one work may not be so in another. For example, the genre of the work may change whether or not the character is overly idealistic. In a work of superhero fiction, a super genius is simply someone with a superpower. In a work of detective fiction, a super genius to too smart to be realistic. So such a thing will count when considering whether or not a character is a Mary Sue in detective fiction but not in superhero fiction. Nonetheless, there are characters who are completely realistic, but because of sheer power, knowledge or friends distort the plot around themselves. Such characters count as a power fantasy or center of attention Sues. Therefore, simply being overly idealistic is too narrow to be a Mary Sue.
There are a number of plausible traits that could be involved in some way in the definition of a Mary Sue. One of these is characters that break the suspension of disbelief by being too good. Another is characters who overcome problems too easily – because of too much power, a lack of flaws, an implausible amount of knowledge or simply an unrealistic amount of luck. Finally, a trait sometimes seen by Mary Sues is distorting the plot by gaining too much attention, or by changing events too easily.
This should be enough to mention two commonalities present in all Mary Sues. All Mary Sues have at least one trait that is too good to be realistic given the genre. It might be accidental to the character (they happen to be too lucky) or it might be essential to the character (they are super intelligent). Second, this trait draws the attention of the reader to the character.
These two traits are sufficient to define the term Mary Sue given the stipulations I have mentioned. Mary Sues are characters who have at least one trait that is too good to be realistic given the genre and the traits draws the attention of the average reader to that character. This means that merely having a trait that is too good to be realistic is not sufficient for a character to be a Mary Sue if that trait is hidden well enough from the reader. It also means that drawing too much attention to the positive yet realistic qualities of a character is not enough on its own for a character to be a Mary Sue.
Aristotle was the first to systematically lay out various living things in the world. According to him, they could be divided into three categories: plants, animals and rational beings (humans). Insofar as biology is concerned, human beings are animals. Therefore, there were two biological categories: plants and animals. Carl Linnaeus extended this knowledge to cover many new kinds of plants and animals, and created more divisions below that of plants and animals. Many of our modern biological categories come from him. The highest division was the kingdom and there were two kingdoms: plants and animals. In 1866, Ernst Haeckel suggested that simple single celled organisms form a third kingdom that he originally called Monera. (He later called this kingdom Protista.) His reasoning behind this change was that biological divisions show historical ancestry (common descent). Modern taxonomists have followed this new pattern and begun a program of categorizing biological things according to ancestry. This is wrong because it is contrary to the purpose of biological categorization.
There are thousands and thousands of different kinds of biological things. There are also many possible ways to categorize them. We might categorize living things by considering how we use them. So weeds refer to plants that we do not want, trees refer to large plants that provide shade, vegetables are edible plants with a similar kind of taste and fruits are plants that have sweet parts. This kind of categorization does not help us understand the living thing. It simply helps us categorize the living thing according to our purposes for it. In fact, any external categorization will not help us understand the living thing. I might name plants according to where they are found, whether I like them, where I bought them or what they can be used for. But these things may vary even if the plant (or animal) stays the same. Furthermore, even if these things do not vary, the explanation for why they do not vary includes knowledge not related to the living thing in question. For example, the reason why pineapples are edible partially has to do with the human digestive system. Finally, even the knowledge about the living thing itself does not unify our knowledge of that living thing. So no externally based categorization scheme is proper if our goal is understanding the living thing itself.
Categorizing living things by their ancestry is an external categorization scheme. The explanation why two living things were placed in the same category would be an external fact (that it is the best fit for those two individuals given the rest of biology). Although historical knowledge is invariant across researchers, it includes both facts about the living thing itself and facts about the rest of the living things that happen to live in the world. Secondly, knowing that dogs and wolves share a common ancestry does not unify our knowledge of dog or wolf biology. Knowing that both dogs and wolves are mammals (and that being mammalian is more fundamental than being a dog or a wolf), does unify our knowledge of either a dog or a wolf.
When we categorize living things we must begin with what is most fundamental, and work our way to what is least fundamental. What is most fundamental to a living thing is the reason why it is alive. Without that, it would not be a living thing at all. Everything else that a living thing does supports the life of that living thing first of all. Least fundamental are the parts of the living thing that can change without harm to that living thing – such as the length of hair, the color of hair or the growth of new branches. Nowhere in this scheme is there room for facts about the ancestry of living things.
The purpose of categorizing living things in biology is to organize them in order to understand them in themselves. The purpose requires categorizing living things according to differences in those living things beginning with the most fundamental differences. Since the differences between living things are purely internal, there is no room for history. Therefore, classification schemes such as cladistics that are based on historical relationships between organisms are universally wrong.