What, then, is "Fundamentalism"? An introductory treatment of the topic.

Somewhat irked by the ease at which people can throw out labels on the internet without accountability, I recently wrote a post entitled "What, then, is a cult?" After reiterating the key scholarly aphorism "Always describe somebody else's position in such a way that they would say that you have described them fairly" (which sounds awfully familiar to Jesus' Golden Rule!), I would like to now post on "fundamentalism."

[Full disclosure: I'm hardly an impartial historian, of course, since my great-grandfather was John R. Rice, and I think rather highly of him, without agreeing with everything he ever wrote]

For some, a Christian fundamentalist is "an evangelical who is mad at something." For others, it is automatically synonymous with KJV-only-ism (there are three levels of this belief: 1. by definition: "the KJV is the only English Bible that should be used"; 2. in extreme form: "the KJV is inspired and inerrant"; 3. in apostate form, "the KJV is the only Bible through which one can get saved"). Consequently, for many people "fundamentalist/fundamentalism" is a derogatory term that is simply slung out there as an insult or completely misunderstood. I recently saw a comment posted on a well-known evangelical theologian's blog suggesting that "fundamentalists" are not even real Christians [ironically, that comment is itself somewhat "fundamentalist"-sounding!].

My purpose here, as a self-identifying moderate fundamentalist belonging to a very conservative fundamentalist church (that, I might add, is doing some great things in pursuing the Great Commission), is to offer the beginnings of a theological definition (as opposed to a sociological definition) and then to point you, dear reader, to some key sources for understanding fundamentalism.

First, fundamentalism is, at its core, a historical reaction to modernism. Consequently one of the best places to start is by  reading The Fundamentals, published between 1910-15, consisting of 90 essays on theological topics written by some of the brighter conservative minds of the day, as well as some of the more eccentric conservative minds of the day. Examples include James Orr on the Virgin Birth, B. B. Warfield on the Deity of Christ, R. A. Torrey on the Holy Spirit, James Orr again on Science and Christian Faith, and W. H. Griffith Thomas on "Old Testament Criticism and New Testament Christianity."

Back in those days, at the origins of modern fundamentalism, the denominational barriers were not quite as strong; today, most self-identifying fundamentalists (at least in North America) are independent Baptist with occasional Methodists and Presbyterians (and contra the general perception of the media, I do not believe the majority of Southern Baptists would consider themselves fundamentalist, though theologically we are often very close).

Initially, fundamentalism and broader evangelicalism were more united in their opposition to modernism. Occasionally the two terms were synonymous; indeed, notable fundamentalists such as John R. Rice and Bob Jones were both involved in the National Association of Evangelicals (my own research in the Wheaton archives reveals the point at which Bob Jones began his split from the NAE). Historically, however, the split between evangelicalism and fundamentalism could probably be characterized as revolving around the inclusive direction Billy Graham began to take with who could participate (as Christian ministers) in his evangelistic revivals [Billy Graham, by the way, was mentored in his early years by John R. Rice]. The final breaking point was the 1957 New York crusade in which Graham partnered with modernist churches; from that point Graham would often allow non-evangelicals, even liberals, to participate in the ministry (as opposed to mere attendance) of the crusades.

This, then, leads us to two key theological points in defining modern fundamentalism:
1. A heavy emphasis on regenerate church membership and fellowship only with other churches that consist (as much as can be discerned) of regenerate membership. 
2. A refusal to ally with modernists in the work of the church. In other words, a doxological focus trumps even evangelism ( the integrity of the Gospel must not be compromised, even in evangelism). The thoughtful fundamentalist views Billy Graham as essentially Jehoshaphat in 2 Chronicles 19:1-3, a great man who nonetheless compromised by making tragic alliances with those who are enemies of God (to be clear, somebody who denies the deity of Jesus or a literal resurrection is an enemy of God).
The above two points more-or-less characterize what we mean by the term "ecclesiastical separation."
3. A corollary to the above two points will generally be a heavy emphasis on avoiding worldliness in matters of culture (including music). This would often be the biggest difference between an Independent Baptist church and a Southern Baptist church: they might be identical in theology, but the Southern Baptist church is more likely to have a drum set and sing CCM songs. 
Some forms of fundamentalism (but not all) would also see modern Bible versions as a sign of worldliness; KJV-onlyism, however, should not be taken as an important aspect of fundamentalism (my own unverified "guestimate" is that even within fundamentalism KJV-only churches are in the minority; the majority of fundamentalist churches such as my own probably still use the KJV, and may consider it the best, but do not consider it to be the only legitimate English translation).

Now, for a theological case for their position by modern Baptist fundamentalists themselves, I recommend the following books:
1. Fred Moritz, Contending for the Faith
2. Rolland McCune, Promise Unfulfilled: The Failed Strategy of Modern Evangelicalism.
3. Mark Sidwell, The Dividing Line: Understanding and Applying Biblical Separation
4. Larry Oats, The Church of the Fundamentalists: An Examination of Ecclesiastical Separation in the Twentieth Century
5. Kevin Bauder and Robert Delnay, One in Hope and Doctrine: Origins of Baptist Fundamentalism 1870-1950 (note: this is a historical discussion with a fairly narrow focus; for a theological treatment, read Dr. Bauder's essay defending fundamentalism in Four Views on the Spectrum of Evangelicalism.
6. Douglas R. McLachlan and Les Ollila, Reclaiming Authentic Fundamentalism.

Finally, for what is in my (limited) opinion the best "outsider" perspective on fundamentalism, see George M. Marsden's Fundamentalism and American Culture.

The word "fundamentalism" has a rich, fascinating, and occasionally sad history as a descriptor of a particular facet of Christianity. For those that wish to critique our position, I suggest pursuing a fair definition of the term and reading at least some of the above sources first, as opposed to simply perusing the "comments" section in a blog or Facebook forum and repeating what you hear.