Favours, whilst I abode in your House, upon account of teaching your
Daughter, and rendred me to be so much Yours, as no less could be
sufficient, than to erect a publick, and as much as in me lay, an
eternal Monument of Gratitude to you. How great the Incredulity of
this Age is, no Man almost knows better than your self; there have
been, and still are, such as boldly deny, that it is possible to bring
the _Deaf_ to speak; others, though they should be admitted to be
Eye-Witnesses, yet would not stick to doubt still of the matter:
Wherefore, what-ever it was that I performed to your Daughter, and to
some others, and by what Artifice I did it, I now ingenuously expose
to the Eyes of all the World. I heartily wish that they may so make
use of this my labour, as that for the future, no more _Dumb_ Persons
may be found.

In the number of these doubting Persons, you have confessed to me,
that you your self had formerly been, until you had heard a certain
Maiden, who before had been _Dumb_, talking with me at _Amsterdam_;
perhaps I should have been so my self, if, when I was ignorant in the
thing, I had received narratively only, that some such thing was
performed by another; wherefore I resolved rather to convince the
Incredulity of Men (which now is accounted Prudence amongst most Men)
of an Error, than to reprove them for their Rashness.

It is now three Years since I first thought to make this my Method
publick; but had I then done it, I should now have repented it,
because in this Interval I have much more polished it; and rendered it
more easie by far; and as to what belongs to the practise thereof,
more certain, yea, and all to that degree, as I dare confidently
assert, that henceforth there shall be no _Deaf_ Person, (provided he
be of a sound Mind, and be not Tongue-tied, nor of an immature Age)