One meaning of the term "Protestant" is "a church drawing its roots from the Reformation and the denominations of the Reformers in particular". I have also seen the term extensively used to mean "a modern non-Catholic non-Orthodox western denomination" with 'modern' meaning dating back no earlier than roughly the time of the Reformation and 'western' generally meaning embracing western scholasticism and enlightenment thinking in general. I have recently been told that the latter meaning is "just wrong". Is the latter definition 'wrong' in some fundamental way and what reasons are there to use or avoid using it? If it is wrong, what term (not "modern non-Catholic non-Orthodox western denomination" please, that's just way too long) would be better for this broader usage?
Humans love to categorise things, and we normally think of categories as dividing things up with borders between the categories. But that isn't actually how we normally do conceptualise our categories - instead we categorise things according to their likeness to archetypes or prototypes, the central most typical examples of a category. The borders between categories are very often hard to determine, but the centres are easy to recognise, which means that your definition is far from ideal because it's all about borders. There's little debate about the most archetypal Protestant churches and the most un-Protestant churches, but it's those in between that are harder to categorise.
The archetypes for Protestantism are the original reformers, people like Luther and Calvin. There are so many attributes that we could describe them with. Here are some I think are most useful for our present day categorisation of Protestants:
- an acceptance of the old ecumenical creeds
- a focus on the Bible
- a rejection of salvation by works
- a rejection of the supreme authority of the Catholic Church
- a focus on personal response to the gospel
Now some of these aren't as relevant today for categorising Protestant churches. Many Protestants have so little contact with Catholics that they aren't really consciously protesting the Catholic Church. We wouldn't want to make that a border of Protestantism because it would keep out many churches that should be included.
The family tree model of denominations doesn't perfectly categorise churches, because sometimes churches break with history. Pentecostals are generally firmly within Protestantism, but Oneness Pentecostals reject the Trinity and are not considered to be Protestant. There will be other churches which do not formally commit to any type of Christology. There are probably many Protestants which (perhaps unknowingly) cross the Chalcedonian division. Making the old creeds a border won't work for every case, but making it an archetype does.
And again, there are many Protestanty churches which no longer give much focus to the Bible. Some reject it's inspiration or infallibility, which means it is much less useful. Others prioritise new relevation over scripture. You can see that the border here would be hard to define, but as a central feature, still is effective.
So I would say that Protestantism refers to churches which are clustered around the archetypal Protestants: Luther and Calvin. What that refers to is fuzzy, but the definition is actually quite precise. (Lexicography is hard you guys!)
Your question is a good one, but it is slightly misguided. You are seeking a precise definition for a term which does not have one. The word Protestant can mean different things depending on the context in which it is used. When used in a historical context, it may be used to strictly refer to those involved in the Reformation and to the churches that they directly founded. However, it is also perfectly legitimate and acceptable to use the term Protestant to refer to any Christians or Churches that espouse the same principles as the original Protestant reformers.
The biggest commonality among Protestants is that they denounce the universal authority of the Papacy. Beyond that, the term Protestant is much like the term Christian. It essentially applies to anyone who chooses to apply it to themselves. In that sense, I do think that you were using the term appropriately, as long as you only intended it in a loose way. It would be wrong to correct someone's use of the term by suggesting that the term can only legitimately be used in a historically precise way.
The latter (the broad) definition is wrong because it results in a heterogeneous set of groups that have nothing in common, and majority of them having no connection to the Reformation. Historically, Protestantism and the Reformation cannot be separated.
For a reasonable definition we must examine what is common to Protestants, and how much of that is needed to keep the term "Protestant" descriptive. The five solas are common to all Protestants according to my perception. They represent the core positions of the Reformation. The solas are:
- Bible alone the final and complete authority.
- Salvation by grace alone.
- Salvation through faith alone.
- Salvation in Christ alone.
- The glory of God alone.
Would this be broad enough? It would be necessary to compromise one or two of these to widen the definition.