Paper long abstract:

How do we justify our reliance on the outputs of the various instruments in science and in our everyday lives? The received view in epistemology has it that the necessary and sufficient condition is that the relevant causal connections must hold. Take a thermometer as an example: there has to be a reliable causal connection between the mercury and certain features in the environment of the thermometer - this is sufficient for the user to acquire knowledge.

I argue that this view ignores the social interactions that are necessary for an instrument to produce its output. The causal connection is a necessary condition for acquiring knowledge via an instrument but it is not sufficient. In other words I try to transmit the emphasis of the interrelations between science and the social and political world that STS brings forward into the realm of epistemology. The social components in our (scientific) knowledge run deeper than the received view would accept.

To illustrate my point I want to use a narrative from the history of thermometry. For a meaningful measurement of temperature it is necessary to have some fixed points where a reliable causal connection can hold, a certain dilation of mercury and a certain state in the world. It turned out that this connection is not simply found in nature but scientists had to agree upon certain conventions to keep the fixed points - boiling and freezing of water - fixed. Their negotiations and agreement is part of what we now call reliably working thermometer.