さて今から三年前，わたしはこれらすべてを内容とする論文を書きあげて，印刷業者の手に渡すために見直しを始めていたのだが，そのとき次の知らせに接した。わたしが敬服する方々，しかも，わたし自身の理性がわたしの思想に及ぼす権威に劣らぬほどの権威をわたしの行動に及ぼす方々が，ある人によって少し前に発表された自然学の一意見を否認した，というのである。わたし自身同じ意見だったと言うつもりはないが，しかし次のことは言っておきたい。その方々の検閲が出るまでは，宗教にたいしても国家にたいしても有害だと想像されそうな点，したがって，もし仮に理性によってわたしが納得したならば，それを書くのを妨げるような点を，少しもその意見のなかに認めなかった，と。そして，きわめて確かな論証をもたないかぎりけつして新しい意見を信用しないように，また，人の不利益になりそうな意見はけっして書かないように，わたしはつねに細心の注意をはらってきたのだが，このような事件があると，それでもやはり自分の意見のなかに何か思いちがいがありはしなかったかと心配になった，と。自分の意見を公表しようとしていたわたしの決意をひるがえさせるには，これだけで十分だった。というのは，以前にこれを公表しようと決意した理由はたいへん強固なものだったが，わたしの性向として，本を出すという職業がいつも嫌だったので，それを断る口実となるほかの理由がすぐ見つかったからである。そしてこういう理由はいずれも，わたしがここでそれを述べておきたいばかりでなく，おそらく一般の人〔公衆〕もそれを知りたいと思われるだろう。
THREE years have now elapsed since I finished
the Treatise containing all these matters;
and I was beginning to revise it, with the
view to put it into the hands of a printer,
when I learned that persons to whom I greatly
defer, and whose authority over my actions
is hardly less influential than is my own
Reason over my thoughts, had condemned a
certain doctrine in Physics, published a
short time previously by another individual,
1 to which I will not say that I adhered,
but only that, previously to their censure,
I had observed in it nothing which I could
imagine to be prejudicial either to religion
or to the state, and nothing therefore which
would have prevented me from giving expression
to it in writing, if Reason had persuaded
me of its truth; and this led me to fear
lest among my own doctrines likewise some
one might be found in which I had departed
from the truth, notwithstanding the great
care I have always taken not to accord belief
to new opinions of which I had not the most
certain demonstrations, and not to give expression
to aught that might tend to the hurt of any
one. This has been sufficient to make me
alter my purpose of publishing them; for
although the reasons by which I had been
induced to take this resolution were very
strong, yet my inclination, which has always
been hostile to writing books, enabled me
immediately to discover other considerations
sufficient to excuse me for not undertaking
the task. And these reasons, on one side
and the other, are such, that not only is
it in some measure my interest here to state
them, but that of the public, perhaps, to
know them.