As the overview article noted, Brugmann was a leading figure of the group known as the Neogrammarians. This article looks at the single most important shift in attitude that group brought into linguistics.

Earlier scholars often shrugged off exceptions as “just how it is”

Nineteenth-century comparative linguistics had, by Brugmann’s time, already turned up plenty of correspondences between languages through the work of Bopp, Grimm, and Rask — patterns where, say, one sound in one language regularly corresponds to a different sound in another. But every such rule turned up a handful of “exceptions.” Some particular word, for no obvious reason, simply refused to follow the pattern.

Many earlier scholars, faced with such exceptions, often settled for the view that “language just has irregularities like this,” without pressing further.

Brugmann’s generation refused to accept that

Brugmann and the other Neogrammarians pushed back hard against this attitude. Whenever they encountered an exception, they tried, systematically and every single time, to pin down the reason why that particular word didn’t follow the rule. Until that reason was found, they held, the research question wasn’t actually finished.

Think of it this way: imagine a class where most students make the same mistake on one test question. Some teachers shrug it off — “that happens sometimes.” Others insist on finding out exactly why so many students got that one question wrong. Brugmann’s generation was unmistakably the latter kind of teacher.

The earlier attitude "Exceptions just happen" reasons sought only occasionally exceptions remain exceptions The Neogrammarians "Every exception has a reason" systematically, every time the search for "why" never stops Facing the same exceptions, the attitude itself changed
How to face an exception — the shift Brugmann's generation made. Diagram: ToL

What this attitude produced

This conviction — that every exception has a reason — is the single biggest turn the Neogrammarians brought to linguistics. And in the course of hunting down these reasons, one of the biggest discoveries they arrived at was a phenomenon called “analogy.” The next article introduces that idea.

Summary

PointDetail
The earlier attitudeExceptions were often left as exceptions, without being pressed further
The Neogrammarian positionSearch systematically for a reason, every single time an exception appears
ConsequenceA research question isn’t finished until the answer to “why” is found

In a nutshell — what Brugmann’s generation changed wasn’t so much a new discovery as a scholar’s whole posture toward exceptions.