and especially the one that agrees with religious doctrine or in any case does not contradict it (argumentum ex verbo). Cf. medieval natural science, where the entire aim is essentia as the real.
Experiri—thus altogether opposed to what is authoritatively proclaimed and to what in general cannot be shown and brought into the light and so is inaccessible to the lumen naturale (opposed to the verbum divinum, "revelation"). Cf. Descartes, Regula III.
This experiri already prior to the Middle Ages: ἐμπειρία, medical doctors—Aristotle! When this—then that! ἐμπειρία, τέχνη already a ὑπόληψις of the "when this—then that" (the rule). But now, through the opposition, an essential significance and especially if a transformation of the human being: certainty of salvation and self-certainty.
Yet this only the general presupposition for the possibility of "experiments," which are thus not given as constituting a necessary and prime component of knowledge. For that, a fundamentally new step is required.
The specific and unique presupposition for experimentation is, as remarkable as it may sound, that science become rational-mathematical, i.e., in the highest sense, not experimental. Initial positing of nature as such.
Because modern "science" (physics) is mathematical (not empirical), it is necessarily experimental in the sense of the measuring experiment.
Sheer idiocy to say that experimental research is Nordic-Germanic and that rational research, on the contrary, is of foreign extraction! We would then have to resolve to number Newton and Leibniz among the "Jews." It is precisely the projection of nature in the mathematical sense that constitutes the presupposition for the necessity and possibility of "experimentation" as measuring.
Now experimentation not only opposed to mere talk and dialectic (sermones et scripta, argumentum ex verbo), but also opposed to arbitrary, merely curiosity-motivated exploration of an indeterminately represented domain (experiri).
Now experimentation a necessary component of exact science, a science which is founded on the quantitative projection of nature and which elaborates this very projection.
Now experimentation no longer opposed only to argumentum ex verbo and "speculation," but also opposed to all mere experiri.
Therefore, a fundamental error and confusion of essential ideas to say (cf. Gerlach10) that because Roger Bacon, for example, discusses
10. E.g., Walter Gerlach, "Theorie und Experiment in der exakten Wissenschaft," in: M. Hartmann and W. Gerlach, Naturwissenschaftliche Erkenntnis und ihre Methoden, Berlin, 1937.—Ed.