I need to find a 18th C. reference that says, basically, that we don't
need God (or man is already as good as God) because we have science
(then known as "natural philosophy"). It should include complete
bibliographic information, e.g., date, pg. no., publisher, place
published, etc. It must be a primary source written from about 1700 to
1740 (after 1750-- not useful, I've already got all I need). It should
not be written by Spinoza or Hume. I've tried chronologies of
atheistic thought in books and some on the web, but suspect that there
are full-text resources or something out there that one of you may
find first. I've also looked in enlightenment philosophy anthologies,
and did several computer searches on secondary sources (that is,
written about, not by, the original author). Some of the terms I've
tried are Newton, Newtonianism, natural philosophy, rationalism,
atheism, deism, enlightenment, reason, science, New Philosphy, New
Science, natural religion, and technology.

The single best work that fits your criteria is probably Alexander
Pope's "Essay on Man" (1733-1734).

Although not atheistic, "Essay on Man" is widely considered a
precursor to the rationalistic "natural philosophy" of the late 18th
century. Epistle II, for example, contains many passages consistent
with enlightenment philosophy. Here are just a couple:

"1 Know then thyself, presume not God to scan;
 2 The proper study of mankind is man."

And:

"19  Go, wondrous creature! mount where science guides,
20   Go, measure earth, weigh air, and state the tides;
21   Instruct the planets in what orbs to run,
22   Correct old time, and regulate the sun;"

For the full text, visit:
http://www.library.utoronto.ca/utel/rp/poems/pope11.html

Here are some articles discussing the relationship between Pope's
"Essay on Man" and the Enlightenment:

http://ca.essortment.com/popeessaychri_rvjn.htm
http://wv.essortment.com/alexanderpopee_rcxe.htm

For more results, try this Google search:
://www.google.com/search?hl=en&lr=&client=googlet&q=%22alexander+pope%22+%22essay+on+man%22+enlightenment&btnG=Google+Search


Some French philosophers of the period also fit your criteria.

Voltaire's "Letters on England" (1734) are generally interpreted as
including enlightenment philosophy. "Letter XIII - On Mr. Locke," for
example, includes quite a bit of discussion about nature, God, and
reason. For full-text, see:
http://www.arts.adelaide.edu.au/personal/DHart/ETexts/Enlightenment/Voltaire/LettersOnEngland1734/Part3.html#anchor166057

Although it was written at the very end of the period, Denis Diderot's
"Philosophical Thoughts", aka "Pensees Philosophiques" (1746) espouses
rationalist philosophy. Here is an excerpt:
 
"It is not from the metaphysician that atheism has received its most
vital attack. . . . If this dangerous hypothesis is tottering at the
present day, it is to experimental physics that the result is due. It
is only in the works of Newton, of Muschenbroeck, of Hartzoeker, and
of Nieuwentit, that satisfactory proofs have been found of the
existence of a reign of sovereign intelligence. Thanks to the works of
these great men, the world is no longer a God; it is a machine with
its wheels, its cords, its pulleys, its springs, and its weights."

[ from a 1916 translation by Margaret Jourdain entitled "Diderot's
Early Philosophical Works," and cited in the article, "The Problem Of
Miracles:
A Historical And Philosophical Perspective," by William Lane Craig
on :
http://www.leaderu.com/offices/billcraig/docs/miracles.html ]


Julien Offray de La Mettrie (1709 - 1751) was another French
philosopher whose views were considered "naturalistic" and
"atheistic." See:
http://www.xrefer.com/entry/552554

Julien Offray de La Mettrie's most famous work "L'homme machine" ("Man
a Machine") (1748) is available on:
http://www.santafe.edu/~shalizi/LaMettrie/Machine/

I hope this helps you in your research. Good luck.

The answer was useful and adequate.  The quotations given me were too
general--I was looking for something which specifically said "we don't
need God because we have science" (I have my own general quotations on
the enlightenment--I'm writing a thesis on the subject).  The problem
is, I don't know whether or not a quote exists and just wasn't found
(I've been searching myself rather extensively for a while), or if
such a quote just doesn't exist.  That being said, the answer given me
did contain some things I can use that I hadn't found before, so I
don't as desperately need the quote (it would still help).

Hi Bode,

I don't have anything by him yet, but is Thomas Paine (born 1737) too late?

CJS

Thomas Paine is a little late, but if he said anything applicable I'd
be interested in hearing it.

Bode

Hi,

This is a little late isn't it? I think don't keep track of all my
Google Answers well enough.

I guess I only mentioned Thomas Paine because his book is called after
all The Age Of Reason. Don't have much else in specifics.

Good luck searching though -- try these words and various combinations
and inflections of them:
"thomas paine god logic(al) reason argument(s) deist/deism
rational(ity)"

Sorry for being two years late, but I think you can find such a quote
by Paul Henri (Baron) d'Holbach, who lived 1723-1789. His most famous
work is "The System of Nature" (1770). I'm not familiar with what he
wrote before that. He wrote under psudonym to avoid being persecuted
for his views so if some of his earlier works contain such a quote, it
may not be known that he is the actual author.

Another famous materialist from the Enlightenment is LaMettrie who may
have written something like that you are searching for in his "Man a
Machine" (1748). Here are some quotes:

"Let us not lose ourselves in the infinite, for we are not made to
have the least idea thereof, and are absolutely unable to get back to
the origin of things. Besides it does not matter for our peace of
mind, whether matter be eternal or have been created, whether there be
or be not a God. How foolish to torment ourselves so much about things
which we can not know, and which would not make us any happier even
were we to gain knowledge about them!"

"After this, let a vain people think otherwise, let them dare affirm
that even probity is at stake in not believing in revelation, in a
word that another religion than that of nature is necessary, whatever
it may be. Such an assertion is wretched and pitiable; and so is the
good opinion which each one gives us of the religion he has embraced!
We do not seek here the votes of the crowd. Whoever raises in his
heart altars to superstition, is bound to worship idols and not to
thrill to virtue."

Most likely, David Hume wrote something similar, but you propably know
more of him than I do.