But even if the more dramatic claim that there has been no scientific progress does not seem compelling, there is a valuable lesson to be drawn from Kuhn’s historical argument. The valuable lesson is that science does not develop in a vacuum. Scientists are human beings, and scientific institutions have connections to funding agencies, economics, politics, and culture at large. At any given time, multiple pressures are affecting how science develops. Some of them are “proper,” having only to do with evidence, observation, experiment, and theoretical integrity. Some of them have less to do with a concern for scientific truth and more to do with the human ambitions and prejudices of the scientists or their bosses.
An example is the 50-year struggle to recognize the toxicity of lead in gasoline. Lead was introduced into gasoline in the 1920s to stop engines from making knocking noises. It was already well known that lead was harmful to living organisms and made people behave erratically, but the scientists employed by fuel companies insisted that the levels of lead in gasoline were safe for human beings. They were not, and the evidence was manifestly clear that the levels of lead were unsafe. Committees were formed and studies were performed, but the results of the studies for several decades was that lead should continue to be put into gasoline and further research should be done. In the 1970s, lead was eventually banned by the newly-formed Environmental Protection Agency. By that time, the average level of lead in people’s bodies in the US was well beyond safe levels, children were underperforming in schools, and crime rates were rising as a direct result of lead poisoning. A similar story can be told of the ways in which scientific studies commissioned by oil companies skewed the data to suppress information about global warming for decades.
In such cases claims to scientific knowledge have been shaped far more by economic considerations than by a proper concern for genuine knowledge. Of course, it is also true that we eventually learned of the effects of leaded gasoline and the effects of carbon emissions on our atmosphere precisely through scientific inquiry once it was freed from the distortions of economics and politics. So the cases of science being distorted by social conditions are not enough to discredit science as a whole. But they are enough to cause us to examine claims to scientific knowledge with some awareness of their social contexts.
And, of course, this point does not apply only to scientists but to all of us. Social conditions shape human knowledge. We will turn to this topic in the next chapter.