The concept of good is central to ethics, morality, philosophy, and religion. It is one of the most widely discussed concepts in these disciplines, and there is considerable debate over what it means to be a good person and to do a good deed. The etymology of the word reveals that its meaning has varied greatly over time and between languages, but most cultures recognize some version of its general idea.

Most ancient philosophers tended to view goodness as having several components, including wisdom, justice, courage, and temperance. Aristotle’s approach was unique, however, in that he conceived of virtue as a mean between two opposite poles, one of deficiency and the other of excess.

Modern philosophical discussions of the good often start with an analysis of a person’s character. The philosopher Jeremy Bentham, for example, thought that to be good required a certain amount of tenderness and empathy with others. He also argued that to be good, a person should try to avoid being unfair, which would make her untrustworthy and thus not a good person.

Other philosophers have emphasized the importance of being honest. Aristotle, for example, viewed honesty as an essential component of being a good person. He regarded dishonesty as one of the worst vices and thought that being dishonest was almost always harmful, although there were some exceptions.

The concept of the good has also been applied to social arrangements and goods, particularly as a measure of their overall value. John Rawls, for example, analyzed the distribution of social goods in order to show that certain kinds of institutions and lives are inherently better than others. His crucial invention was the original position, a procedure for making objective moral decisions that attempts to exclude personal facts from the decision-making process.

Another important feature of the good is its suitability for a particular purpose. A good is a thing that promotes success, welfare, or happiness. An example is a long walk through crowded streets, which is good for someone who enjoys people-watching. A good is also a tool that is effective or efficient. A good tool is easy to use and produces the desired result.

The word “good” is also used adverbially to express satisfaction, pleasure, agreement, or approval. It is contrasted with the adverb well, which is standard and colorless and generally carries a negative connotation. For this reason, the adverb good is used in most exclamatory sentences and in writing that is meant to be informal or familiar.