Experimental Systems in the Co-Construction of Scientific Knowledge**

The publication of Toward a History of Epistemic Things 25 years ago was a landmark in science studies. Not only was the book a brilliant overview of new research trends, but it was also a personal and highly original contribution because of its emphasis on the major role of experimental systems in the construction of scientific knowledge. The paths that it opened have not yet been fully explored. More seriously, the ambition of the author to reinforce the value of scientific knowledge by the role of experimental systems in its construction has not been pursued.