Collective Knowledge
The difference between individual and collective knowledge is the difference between individual belief and collective acceptance. Just as an individual knows P if she believes P, P is true, and there is no important gap in her information about P, so too P belongs to the collective stock of knowledge of a group of individuals if P is collectively accepted by the group, P is true, and there is no important gap in the group’s collective information about P.
Although two kinds of knowledge have the same structure, there are complex questions about their relationship. Some of these questions revolve around the constitution of the groups that can collectively accept and, if all goes well, collectively know something. How narrow or broad can these groups be? Can a group as large as all the people currently alive be said to have collective knowledge of something? What about a group as narrow as the members of a single household? And, how loosely organized can a group be and yet still collectively accept and know something? Is it possible for all individuals with green eyes to have collective knowledge? Or do the individuals have to be spatially, temporally, or culturally linked in characteristic ways? If so, what are these ways?
Intriguing as such questions are, for purposes here the most pressing questions are ones about the relationship between collective acceptance by a group and the beliefs of the individuals making up the group, however that group is defined. Collective acceptance and individual beliefs, and hence collective knowledge and individual knowledge, are linked but not as straightforwardly as one might initially suppose.
The simplest way for a claim to be collectively accepted by a group (community, society, etc.) is for enough individuals within the group to believe the claim, but collective acceptance is not always a matter of sheer numbers. Even when only a few individuals believe a claim, it can nonetheless become collectively accepted and known, provided these individuals have the requisite intellectual standing within the group.
This is a particularly important point in our era of intellectual specialization, where experts have rapidly expanded the collective stock of knowledge and have done so in fields so specialized that only a very few highly trained individuals are in a position to understand, much less evaluate, the propositions in question. Public assertions of a proposition P by highly trained experts can nonetheless lead to collective acceptance and knowledge if others are prepared to defer to them. The “others” here include not only nonexperts but also other experts who begin to rely on P in their own investigations.1
The phenomenon of experts relying on the work of other experts is an important aspect of the symbiotic relationship that exists between individual and collective knowledge. Intellectual breakthroughs in a specialized field by a few individuals can add to the collective stock of knowledge, which lays the groundwork for further advances by other individuals in the field itself but also in related fields, which in turn can lead to yet additional growth in collective knowledge, and so on.
The discoveries of Copernicus in the sixteenth century, Kepler in the seventeenth, Lavoisier in the eighteenth, Maxwell in the nineteenth, and Einstein in the twentieth were possible only because previous investigators had built up collective stocks of knowledge that these investigators made ingenious uses of. Their discoveries then added to the collective store of knowledge, thus putting future investigators in an improved position to make yet further discoveries.
As these examples suggest, collective knowledge is especially important in science. C. S. Peirce famously argued that the collective nature of scientific inquiry is an essential component of scientific rationality. His argument, briefly stated, was that unless individual scientists had trust in the community of future inquirers and saw themselves as a part of this community, there would be little point to their work. There would be little point, he thought, because the goal of scientific inquiry is nothing less than a complete and final account of whatever is being investigated, but given the relatively early stage of human intellectual history and the relative shortness of human lives, it is not realistic for individuals on their own to achieve this goal, at least not for topics of significance. Peirce thus concluded that individual scientists must, as a condition of rationality, view themselves as part of a temporally extended community of inquirers, a community that will continue its work well into the future. For it is only by identifying oneself with such a community and by focusing on one’s role in increasing collective knowledge that one has a realistic chance of achieving the principal intellectual goal in doing science, namely, a final, fixed treatment of the topic one is investigating.2
It is questionable whether the aim of scientific inquiry cannot be anything less than a complete and fixed account of what is being investigated, as Peirce presupposes, but this presupposition aside, he is on to an important point. Despite the remarkable achievements of individual scientists, science is at its heart a collective enterprise, albeit a collective enterprise driven forward by individual effort and achievement.
The key mechanism for incorporating individual achievement into the collective enterprise is the division of intellectual labor. Reduced to its bare bones, the system works by breaking problems into components, providing incentives for investigators to develop highly refined expertise in these narrowly defined components, and requiring them to make available to other investigators the specialized information they acquire.
The signs of ever-increasing specialization in the sciences are everywhere. One is no longer a specialist in physics but rather a specialist in theoretical high-energy physics, or even more specifically in string theory. Similarly, one is not so much a life scientist as a molecular biologist and not so much a molecular biologist as a molecular geneticist.
A widely noted consequence of this ever more fine specialization is that nonspecialists, even highly educated ones, lack the background needed to assess work being done in specialized fields. An authority on Renaissance literature is not in a position to evaluate the latest developments in string theory.
This is the point that so worried C. P. Snow with his reference to “the two cultures” of the sciences and the humanities.3 What is less widely noted is that fellow scientists are not in a much better position. Biologists lack the training and background required to evaluate developments in string theory, and for that matter so do most other physicists. Similarly, string theorists are not especially well positioned to assess recent developments in molecular genetics, and neither are geologists or condensed matter theorists.
There is a reinforcing dynamic at work here. The division of intellectual labor and the accompanying increased specialization of knowledge produce a vastly expanded stock of collective knowledge, but this vastly expanded stock in turn makes further specialization increasingly inevitable because it is no longer feasible for even the brightest, most encyclopedic individual to master even a small fraction of that which is collectively known.
There is no point bemoaning this trend. It is the to-be-expected consequence of the above dynamic with its emphasis on collective knowledge. One of the most important changes in intellectual life over the past several hundred years is the increasingly large gap between individual knowledge and the collective stock of knowledge. Moreover, the gap is widening even for the most highly educated.
Consider a leading contemporary scientist, the physicist Steven Hawking, for example. Drawing upon work of multiple generations of previous physicists, Hawking has a far more accurate and comprehensive understanding of the physical world than did Archimedes, DaVinci, Galileo, or Newton. On the other hand, Archimedes, DaVinci, Galileo, and Newton had knowledge of a greater percentage of the collective knowledge of their eras than Hawking has of the collective knowledge of our time. Not because Hawking is any less bright, energetic, or curious. The explanation, rather, is that individual scientific knowledge cannot keep pace with increases in collective scientific knowledge.
The widening gap between individual and collective knowledge has major social, political, and educational implications, and given its centrality, it is still underappreciated. I too, however, will be sidestepping the issue, since the key issue for purposes here is that science at its heart is a collective enterprise. In recent years, observations about the social dimensions of science have tended to be prefatory to raising doubts about its claims to objectivity, but this is not my point. Mine is the claim that science is a social enterprise in the sense that its central aim is the expansion of collective knowledge.
On the other hand, the principal tool for accomplishing this aim is the division of intellectual labor, which encourages individual scientists to acquire extraordinarily detailed information about the components of larger scientific problems so as to minimize the likelihood of there being important gaps in their understanding of these component issues. This is just to say that it encourages the acquisition of individual knowledge in the service of collective knowledge.