be no certainty
that knowledge will continually progress until science has been
placed on sure foundations. And science does not rest for us on sure
foundations unless the invariability of the laws of nature is admitted.
If we do not accept this hypothesis, if we consider it possible that the
uniformities of the natural world may be changed from time to time, we
have no guarantee that science can progress indefinitely. The philosophy
of Descartes established this principle, which is the palladium of
science; and thus the third preliminary condition was fulfilled.

2.

During the Renaissance period the authority of the Greeks and Romans
had been supreme in the realm of thought, and in the interest of
further free development it was necessary that this authority should
be weakened. Bacon and others had begun the movement to break down this
tyranny, but the influence of Descartes was weightier and more decisive,
and his attitude was more uncompromising. He had none of Bacon's
reverence for classical literature; he was proud of having forgotten the
Greek which he had learned as a boy. The inspiration of his work was the
idea of breaking sharply and completely with the past, and constructing
a system which borrows nothing from the dead. He looked forward to an
advancement of knowledge in the future, on the basis of his own method
and his own discoveries, [Footnote: Cf. for instance his remarks on
medicine, at the end of the Discours de la methode.] and he conceived
that this intellectual advance would have far-reaching effects on the
condition of mankind. The first title he had proposed to give to his
Discourse on Method was "The Project of a Universal Science which can
elevate our Nature to its highest degree of Perfection." He regarded
moral and material improvement as depending on philosophy and science.

The justification of an independent attitude towards antiquity, on
the ground that the world is now older and more mature, was becoming a
current view. [Footnote: Descartes wrote: Non est quod antiquis multum
tribuamus propter antiquitatem, sed nos potius iis seniores dicendi. Jam
enim senior est mundus quam tune majoremque habemus rerum experientiam.
(A fragment quoted by Baillet, Vie de Descartes, viii. 10.) Passages
to the same effect occur in Malebranche, Arnauld, and Nicole. (See
Bouillier, Histoire de la philosophie cartesienne, i. 482-3.)

A passage in La Mothe Le Vayer's essay Sur l'opiniatrete in Orasius
Tub