Are there other concepts comparable to the complexity of art?

Question:  What are some other concepts that are so complex, we have trouble defining them?

After our discussions in class, I have found a few other concepts, in addition to art, that are so complex, we have trouble defining them. One concept that we have trouble defining is time. Time is very hard to define because in defining the word, we can't use the word in the definition. For example, one might define time as, "A specific amount of time." This would not work because "time" is used in the definition, and if the reader does not know what "time" means, they will not understand the definition. This would be particularly confusing if you are teaching someone a new language because they would not know what the word "time" means in English, and it would be really hard to explain the concept to them if the teacher did not know the equivalent word to "time" in the person's native language. It is quite difficult to try to define time without using the word in the definition. Time is a very complex concept, making it very hard to define. Therefore, there has been a lot of controversy over the years on how to define it adequately.

Another complex concept that is difficult to define is love. I think one of the reasons it is so hard to define is because it involves many different emotions, that are hard to put into words. It is hard to describe in words a feeling that feels so powerful and significant inside. Another possible reason for its complexity is that there are different kinds of love. One feels different kinds of love toward their parents, spouses, children and friends. When someone says "I love you," to their children, it means something different than when they say the same thing to their spouse. I wouldn't say that these are different levels of love, because one can love their parents and family just as much as they love their spouse. Rather, they are different kinds of love. Consequently, people have also debated over the years what the adequate definition of love would be. 

Do we need definitions?

      Question:   Some would argue that certain concepts, or objects, do not require definitions because they have certain known characteristics that distinguish them from other things. For example, we know the characteristics of a cat; therefore we no longer need a definition for it. However, wouldn't definitions be necessary when it comes to teaching and/or learning a new language, especially if the concept is specific to one culture, and therefore does not have an equivalent in any other languages?

      I have concluded that yes, definitions would be necessary in this situation because if teaching someone a new language, we would need to describe the characteristics of new words, therefore defining them. By describing the characteristics of the new word, we are giving a definition, whether or not it is exactly the same definition that would be found in a dictionary. Definitions just list the characteristics of the word, or the necessary and sufficient properties that something needs to have in order to be called that word. 

      If we didn't have definitions, listing necessary and sufficient characteristics, we wouldn't be able to discriminate between different objects. For example, if we didn't have a definition for the word cat, we wouldn't be able to discriminate between what is and what is not a cat. People could start claiming that dogs are cats, and it would be justifiable because there is no definition to act as a reference. We also need these definitions to be specific enough to make sure that things that do not belong are not being included in the definition. For example, if the definition for a cat was, "an animal with four legs, eyes, ears, a nose, a mouth, and a tail," then we could claim that many reptiles are cats because they meet these characteristics. Therefore, not only do we need definitions, but these definitions must also list necessary and sufficient characteristics that are specific enough to exclude any objects that do not adequately fit the term.