The basic assumption in modern science "is a widespread,
instinctive conviction in the existence of an Order of Things, and in particular,
of an Order of Nature." This belief, this faith, for at least since
Hume it must be recognized as such, is simply "impervious to the demand
for a consistent rationality." In the systems of scientific thought
of Galileo, Newton, and of their successors, the testimony of experiment
is the ultimate criterion of truth, but the very notion of experiment is
ruled out without the prior assumption that Nature constitutes an intelligible
order, so when appropriate questions are asked, she will answer so to speak.
Hence this assumption is final and absolute (1968, pp. 635-636).