Question

Prior to Karl Verner’s landmark 1876 paper, comparative linguists studying Indo-European sound shifts faced a persistent anomaly in Grimm’s Law. Formulated in 1822, Grimm’s Law systematically accounted for the consonant shifts from Proto-Indo-European to Proto-Germanic, such as the voiceless stops $p$, $t$, and $k$ evolving into voiceless fricatives $f$, $\theta$, and $x$. However, in certain medial positions, these expected voiceless fricatives systematically yielded voiced stops or voiced fricatives instead—an inconsistency that led contemporaries to dismiss sound laws as mere probabilistic trends rather than exceptionless rules. Verner hypothesized that these apparent irregular exceptions were not random mutations, but were conditioned by the placement of the pitch accent in Proto-Indo-European before it shifted to the initial syllable in Proto-Germanic. By correlating Germanic consonant variations with the accentual patterns preserved in Vedic Sanskrit and Ancient Greek, Verner demonstrated that when the accent did not immediately precede the voiceless stop, the consonant underwent voicing. Verner’s formulation—subsequently named Verner’s Law—did not merely resolve a localized phonological puzzle; it fundamentally rescued the Neogrammarian doctrine that sound laws operate with blind, exceptionless necessity. By demonstrating that apparent anomalies stemmed from unobserved conditioning factors rather than inherent volatility, Verner established comparative historical linguistics as a rigorous empirical discipline capable of systematic prediction.

Which of the following can be inferred from the passage regarding comparative historical linguistics before the publication of Verner’s Law?