Ptolomey and Copernicus were they that have had the honour to
see farthest into, and discourse most profoundly of the Worlds
Systeme. About the Works of which famous Men these Dia­
lous being chiefly conversant, I conceived it my duty to De­
dicate them only to Your Highness. For laying all the weight
upon these two, whom I hold to be the Ablest Wits that
have left us their Works upon these Subjects; to avoid a Sole­
cismein Manners, I was obliged to address them to Him, who
with me, is the Greatest of all Men, from whom they can re­
ceive either Glory or Patrociny. And if these two persons
have so farre illuminated my Understanding as that this my
Book may in a great part be confessed to belong to them, well
may it also be acknowledged to belong to Your Highness, unto
whose Bounteous Magnificence I owe the time and leasure I
had to write it, as also unto Your Powerful Assistance, (never
weary of honouring me) the means that at length I have had
to publish it. May Your Highness therefore be pleased to accept
of it according to Your accustomed Goodness; and if any
thing shall be found therein, that may be subservient towards
the information or satisfaction of those that are Lovers of
Truth; let them acknowledge it to be due to Your Self, who are
so expert in doing good, that Your Happy Dominion cannot
shew the man that is concerned in any of those general Cala­
mities that disturb the World; so that Praying for Your Prospe­
rity, and continuance in this Your Pious and Laudable Cu­
stome, I humbly kiss Your Hands;

Your Most Serene Highnesses

Most Humble and most devoted

Servant and Subject

GALILEO GALILEI.