The etymology of the word ‘spirit’ is ‘breath’ or ‘wind’; the Greek word ‘Pneuma’ and the Latin word ‘spiritus’ can both mean spirit or breath. As there are other words in these two languages that have overlapping meanings (‘anima’ in Latin can mean breath, wind, soul or mind) so the whole area becomes confusing. Perhaps there are several distinct phenomena referred to by these words; a soul and a spirit might be two different things. Else, the same word might refer to different things in different contexts. It is further complicated by the use of the word ‘spirit’ in a metaphore.
Spirit can be used to refer to an individual’s general behaviour and attitude. It does not refer to an individual act or comment but an ongoing part of the person’s existence; the tendency to think an act a certain way is a pattern that we can refer to as their spirit. The spirit does not refer to their physical body, but the ongoing way they act, the ongoing way that they are.
In a similar way the word spirit can refer to the attitude of society. The term ‘Zeitgeist’ or spirit of the times (attributed to G. W. F. Hegel) refers to the attitude of the society at a particular point in history. With this understanding the spirit of early 20th century Europe and America was optimistic and inclined towards progress; the spirit of famine stricken medieval Europe was pessimistic and believed the world was ultimately unchanging. Spirit here refers to the overall perspective and not one isolated event.
We are used to hearing phrases such as ‘spirit of the law’ or ‘written in the spirit of’. This is a metaphoric use of ‘spirit’ which juxtaposes a literal interpretation of a law with its intension, or seeks to find the mentality that produced certain written work. Again, the spirit refers to an overall tendency rather that an individual element,
The link between ‘spirit’ and ‘breath’ are understandable given how essential breathing is for all living beings. If we die we stop breathing, and the spirit departs. This is true no matter which understanding of spirit we prescribe to. Those who believe in the supernatural can claim the spirit continues elsewhere; others, that the spirit has died too.
Ultimately spirit always seems to refer to something that is not explained, or not explained easily, by the existence of physical matter. It is invisible, but produces visable effects. This need not imply the existence more than the physical, of something supernatural, only the acknowledgment of the mental, or something that results from the extreme complexity or interacting matter. As a noun refers to an object so a verb may refer to an action performed on or by that object. A materialist ‘physical matter only’ understanding of the world could loosely equate nouns with matter and verbs with spirit; spirit would be a process of the physical matter. Acknowledgment of the supernatural, however, can put the spiritual first and make matter subordinate; matter is moved by the spirit that inhabits it. Some confusion still remains as many religious writings use the word ‘spirit’ in both supernatural and physical senses. Context should provide some clue as to the intended meaning.