even when the events are successefull, no glory is
merited thereby. Every Art hath its certain rules, which by
infallible means lead to the ends proposed; and provided that an
Architect takes his measures right, he is assured of the beauty of
his Building. Believe not for all this, Reader, that I will conclude
from thence my work is compleat, because I have followed the rules
which may render it so: I know that it is of this labour, as of the
Mathematical Sciences, where the operation may fail, but the Art
doth never fail; nor do I make this discourse but to shew you, that
if I have left some faults in my Book, they are the effects of my
weakness, and not of my negligence. Suffer me then to discover unto
you all the resorts of this frame, and let you see, if not all that
I have done, at leastwise all that I have endeavoured to doe.

Whereas we cannot be knowing but of that which others do teach us,
and that it is for him that comes after, to follow them who precede
him, I have believed, that for the laying the ground-plot of this
work, we are to consult with the Grecians, who have been our first
Masters, pursue the course which they have held, and labour in
imitating them to arrive at the same end, which those great men
propounded to themselves. I have seen in those famous _Romanzes_ of
Antiquity, that in imitation of the Epique Poem there is a principal
action whereunto all the rest, which reign over all the work, are
fastned, and which makes them that they are not employed, but for
the conducting of it to its perfection. The action in _Homers
Iliades_ is the destrustion of _Troy_; in his _Odysseas_ the return
of _Ulysses_ to _Ithaca_; in _Virgil_ the death of _Turnus_, or to
say better, the conquest of _Italy_; neerer to our times, in _Tasso_
the taking of _Jerusalem_; and to pass from the Poem to the
_Romanze_, which is my principal object, in _Helidorus_ the marriage
of _Theagines_ and _Cariclia_. It is not because the Episodes in the
one, and the several Histories in the other, are not rather beauties
than defects; but it is alwayes necessary, that the Addresse of him
which employes them should hold them in some sort to this principal
action, to the end, that by this ingenious concatenation, all the
parts of them should make but one body, and that nothing may be seen
in them which is loose and unprofitable. Thus the marriage of my
_Justiniano_ and his _Isabella_, being the object which I have
proposed unto my sel