Descartes: A Biography

c CUNYB/Clarke     December, :

The ScientificEssaysand theDiscourse on Method 

Huygens, who was then involved in military manoeuvres with the army

of Prince Frederik Hendrik. France declared war on Spain in May,

and planned a joint offensive against the Spanish Netherlands, with the

French marching from the south and the Dutch attacking from the north.

Despite the urgent demands of the court and army, Huygens enters fully

and personally into trying to persuade Descartes to publish some sections

of his work. He writes from a military camp at Panderen,October,

pleading with Descartes not to be impeded in his project ‘by any of the

imaginary considerations which have hitherto held you in scruples’ (i.).

He identifies an alternative publisher, Willem Blaeu in Amsterdam; he

advises Descartes to use woodcuts rather than copper plates for printing

diagrams; and he even suggests that the diagrams be printed throughout

the text rather than collected all in one place at the end of the volume.

Descartes reports to Mersenne, about the same time, that since the

condemnation of Galileo he has completely revised a treatise that he had

begun previously, presumably theDioptrics,oratleast those parts ofThe

Worldthat refer specifically to light.In passing, he also criticizes the idea

that weight is a ‘real quality’ in bodies (i.), a feature of his theory of

explanation that recurs frequently in later years, and he expresses surprise

that Mersenne would dare to criticize Morin’s defence of the Earth’s

immobility.

By November, Descartes’ plans for his publication were begin-

ning to come into focus. He decided to include theMeteorstogether with

theDioptricsand, for the first time, he mentioned his ambition to add a

Preface to the book, which he thought was likely to delay completion by

two or three months (i.). It is clear that theDioptricswas already near

enough to completion, by December,torefer to its contents as if

the structure of the book were fixed (i.). Descartes’ correspondence

seems to lapse in December, and the date of the next surviving letter

is three months later, in March.Bythat time the plague that had

affected Leiden during the previous winter had cleared, and he had final-

ized enough of his manuscript to show it to various printers with a view to

publication.

Leiden,

Once arrived in Leiden, Descartes began to discuss publication of his

book with Elzevier. The publisher raised many difficulties and assumed,