Aristotle defines a virtue as a(n) that requires

Aristotle illustrates virtue in a way distinct from what one is usually taught in school, but it is much closer to how one thinks on a regular basis. One is usually taught that courage is the contrary of cowardice, and generosity is the reverse of miserliness and others.  

Although, Aristotle illustrates virtue as the mean between the two extremes, which requires to be avoided. For Aristotle, virtue is the golden mean between the two extremes. Though the mean is not a strict arithmetic mean. Virtue comes in between the two extremes, but where it actually comes depends on a very large extent to a particular situation.  

biology is the study of life. it is the study of living organism.