Ever since the beginnings of modern philosophy of science its practitioners realized that facts are based on human decisions. In spite of attempts of logical positivists in the early 20th century to distinguish ideology from truth, even they could not deny that implicit or explicit argumentation preceeds every scientific fact.

In fact, in science, reasoning is of a more fundamental interest than counting. Scientist who initially reject this idea, are easily persuaded by an example that strikes their own interests: the quantification of their output. What can be counted as scientific output or a citation?

Like no others perhaps, the CWTS staff get feedback about how much their numbers are based on reasoning and consultation.

All counting first requires a definition of the to-be-counted. When does an object in space count as a planet, an organism as an animal, and a human being as intelligent or as man or woman? Couldn't we just as well use more - or perhaps even less -categories than the divide between dull and intelligent people, or males versus females, animals against humans?

Trudy Dehue discusses how different strands in philosophy of science have thought about this issue. Initially the fundamental uncertainty of all knowledge was emphasized, but later the conviction grew that science indeed is about reality, albeit a reality largely shaped by itself. What should the consequences be of this conclusion?