Tacit Knowledge, Replication, Expertise, and Democracy

Summary

Replication and its converse, falsification, are rightly seen as important parts of scientific practice, but neither is straightforward. The agreement needed to categorize an experiment as a successful replication or a decisive falsification depends on a wide range of contextual—that is, non-epistemic—factors. Chief among these is tacit knowledge, which refers to knowledge held by scientists that is not articulated explicitly and can be gained only through social interaction. In scientific disputes, the crucial elements of tacit knowledge are the somatic (i.e., embodied) tacit knowledge needed to build or manipulate the experimental equipment and the collective (i.e., social or cultural) tacit knowledge needed to make judgments about the skill and trustworthiness of other scientists.

Collective tacit knowledge (CTK) is particularly important in novel research, as judgments about the competency of experimenters are the only way to distinguish between conflicting results. Once a sufficiently widespread agreement is reached, all aspects of the controversy—which is the correct theory, which experiments are to be relied upon, and which scientists have the necessary skills—are resolved simultaneously; up until this point, everything remains in flux. Determining whether the outcome of an experiment is a successful replication is an example of the much more general problem of induction. Emphasizing the role of tacit knowledge, and CTK in its resolution, reveals that it is a sociological problem as much as an epistemological one. Not only does solving the problem require a social judgment to be made, but it also creates a new, shared agreement about how the world is to be understood and interpreted from that point on.

Recognizing that science routinely solves the problem of induction gives rise to a new way of understanding its role in democratic societies. Traditionally, science was seen as providing the facts upon which public debate and policy could be built. While this remains an important contribution, the rise of increasingly authoritarian forms of populism within what were once called the “Western democracies” has highlighted a new, more vital role for science as a source of values. Populist regimes need to undermine the checks and balances of democracy, and a crucial part of this is portraying the leader as the sole source of authority on matters of truth, even when this is contradictory to or inconsistent with the evidence. In these circumstances, the value of science is not that it provides “better truth” but that it embodies and defends the idea of truth itself. Without this as an aspiration, democracy and justice—themselves also aspirations—will be lost.