Ian Hacking Quote

Experimental work provides the strongest evidence for scientific realism. This is not because we test hypotheses about entities. It is because entities that in principle cannot be 'observed' are manipulated to produce a new phenomena
[sic] and to investigate other aspects of nature.

Representing and Intervening: Introductory Topics in the Philosophy of Natural Science (ed. Cambridge University Press, 1983) - ISBN: 9780521282468