When Rapid Diffusion Is Evidence For and Against an Idea
2026-07-20 · AI-generated insight
Degler and Wade describe the same historical event — Boas's culture concept sweeping through the social sciences — but assign it opposite meanings, and the disagreement turns on what rapid diffusion of an idea signifies.
For Degler, the speed with which Boas's framework "conquered his own field" and spread beyond it reads as testimony to its power: a genuinely seminal contribution winning on merit, with social scientists across disciplines volunteering their conversion. For Wade, the very same triumph is suspicious. An idea "designed to support" a political conclusion doesn't need to be true to spread quickly — it needs to be useful. On his reading, the diffusion happened not because the evidence was overwhelming but because the doctrine relieved an entire generation of scholars from an uncomfortable question.
The deeper problem is that both explanations predict the same observable history. Ideas spread fast when they're correct and fill an explanatory vacuum; ideas also spread fast when they're politically convenient and fill a moral vacuum. Boas's culture concept plausibly did both at once — it arrived as scientific racism was producing real horrors, so its truth-value and its moral utility were bundled together from the start. That bundling is exactly what makes the case so hard to adjudicate a century later: anyone questioning the doctrine looks like they're questioning the moral commitment, and anyone defending it can't easily prove they aren't just defending the commitment.
Degler's own detail sharpens this. He notes Boas himself used "culture" conventionally until the 1890s — the concept was forged, not inherited, which means it was shaped by the pressures of its moment. Wade would say: shaped by politics. Degler would say: shaped by evidence Boas gathered. The honest position may be that a single individual redirecting an entire field is precisely the scenario where these two forces are hardest to disentangle — there's no independent replication of a founder, only followers. The pairing suggests a useful heuristic: when an idea's adoption curve is steepest, ask what else it was doing for its adopters besides explaining the data.