Adam received six laws from God in the Garden of Eden . The seventh was given to Noach and his descendants. The purpose of these laws was to be the foundation of just and godly societies throughout the world. However, it was in the generation of Enosh that mankind became confused as to what was expected of them by their Creator. At first, mankind reasoned that if God created the moon and the stars and gave them power and influence over mans lives  that just as one should praise and honour the King, one should also praise and honour His appointed servants. This concept, known as shituf, entails ascribing partnership to God.
In time, mankind became even more confused with regards to the Noachide Laws and what was expected of them. The objects which had once been worshipped as mere tools, with no independent powers of their own, became the exclusive focus of worship. What mankind had stumbled onto was Avodah Zarah, idol worship. Moreover, mankind had so forgotten the Laws that were commanded to Adam that their behaviour had become completely immoral and unjust. They reached such degraded level that God found it necessary to cleanse the earth  and to start again, as it were, with Noachs family.
But even with The Flood in mankinds collective memories, this did not stop mankind from starting its descent again into injustice and immorality. However, throughout history, there had always been individuals who had preserved the Laws as they should be and had not deviated from the path set for them by God. Even though all around them were becoming confused as to what God expects of mankind, individuals remained who adhered to the proper path. From Adam to Noach was ten generations. From Noach to Abraham was ten generations. However, because of the antediluvian life spans, only three generations were needed to teach the laws to Abraham .
With Abraham, God saw that in order to bring mankind back to the Laws He had originally given to mankind, a specific group of people would be required to present an example to the Nations and to safeguard the Noachide Laws for the rest of Mankind. Out of the forging press of Egyptian Exile emerged a people that could stand around Mount Sinai and declare that they accept the special mission assigned to them by God. That mission is to be a Light Unto the Nations . That mission is to bring the Nations back to the path that they had originally deviated from.
The Noachide Laws thus became part and parcel of the Revelation at Sinai. The Bnei Noach (Sons [and Daughters] of Noach) are no longer meant to keep the Laws merely because they were originally given to Adam and then to Noach. The Bnei Noach are now required to keep the Laws because they are the Will of God for all mankind as expressed in His Torah.
The Torah that God gave to the Bnei Yisrael is in two parts. The first, which most people are familiar with, is the Torah she bichtav, the Written Torah. What few people realise is that God gave the Bnei Yisrael explanations of and methods for deriving His Will from the Written Torah. This is known as the Torah she baal peh, the Oral Torah . There is a fundamental principle in Torah Judaism that every part of the Oral Torah can be found hinted at in the Written Torah. Using these methods of exegesis, the Mishna in Sanhedrin 56a derives the Noachide Laws given to Adam from Genesis 2:16. The Seventh Law is recorded outright to Noach in Genesis 9:4. They are formalised by the Rambam  in his monumental Codification of Torah Law, Mishne Torah, Section Hilchot Melachim (The Laws of Kings), 9:1.
- Avodah Zarah The prohibition against idolatry
- Birkat HaShem The prohibition against blasphemy
- Shefichut-Damim The prohibition against murder
- Gilui Arayot The prohibition on sexual immorality
- HaGezel The prohibition against theft.
- HaDinim The command to establish laws and courts of justice
- Ever min haChai The prohibition against eating the limb of a living animal.
The derivation of the first six laws From Genesis 2:16 is accomplished as follows:
VAYITSAV HASHEM ELOKIM AL HAADM LEIMOR MICHAL EITS
And Hashem God commanded the man, saying, Of every tree of the garden you may freely eat.
Idolatry: TSAV (command). As evident from Hosea 5:11, TSAV is an allusion to the worship of idols. There, the word TSAV is used directly in reference people doing the command (TSAV) of idolatrous priests (Rashi) and the wicked kings (Radak).
Blasphemy: HASHEM (God). The word develops an association between this verse and the prohibition against cursing God mentioned in the verse Leviticus 24:16, which explicitly uses the name HASHEM.
Murder: AL HAADAM (To the Man). The words refer to the command against murder as mentioned in Genesis 9:6 where the word ADAM is also used to describe man.
Sexual Immorality: LEIMOR (saying). The word LEIMOR establishes a connection between this verse and Jeremiah 3:1, which starts with the word LEIMOR. Jeremiah 3:1 discusses acts which are sexually immoral.
Theft: This is derived from the plain meaning of the verse to granting license to eat from the trees of the garden for otherwise Adam would have been forbidden to do so, because the property did not belong to him.
Courts of Justice: ELOKIM (God). Exodus 22:27 uses that Name in reference to judges and the judical process.
Flesh from a Living Animal: Nevertheless, you may not eat flesh with its life, which is its blood. This is not derived from Genesis 2:16. Rather, from the plain meaning of Genesis 9:4.
In the words of the Rambam, Anyone who accepts upon
themselves the fulfilment of these Seven Laws and is precise in their observance
is considered one of the Righteous of the Gentiles and will merit a share
in the World to Come. What I have listed above is only a simple
overview of the Noachide Laws. For further information, please
feel free to contact me; either through e-mail or, if you prefer, at ICQ #33631317.You can also learn more about the Noachide Laws by visiting Rachav's Bnei Noach Page. She is a Bat Noach [Daughter of Noach] residing in Melbourne, Australia.
 Genesis Rabbah 16:6. Sanhedrin 56a, however, states that seven laws were commanded to Adam. Since the consumption of meat was not performed until the time of Noach, the seventh law would have been irrelevant to Adam and his descendants. Thus, Seven Laws would, retroactively, be Six Laws.
 In the sense of tides, seasons, etc.
 Major commentators, such as Rashi and the Ramba"n say that The Flood was an event local to the Land of Israel and immediate environs only.
 Adam (1 930) to Lamech (874 1561) to Noah (1056 2006) to Abraham (1948 2123).
 Isaiah 42:6, Isaiah 49:6 Isaiah, 60:3.
 For example, Then thou shalt kill of thy herd and of thy flock... as I have commanded thee" (Deuteronomy 12:21). An examination of the Jewish Bible from cover to cover would reveal that no mention is made of the process that was commanded the Israelites regarding the slaughtering method. Thus, it is rational to assume that the directions existed as a body of knowledge outside of the Torah she bichtav: The Torah she ba'al peh.
 Rabbi Moses Maimonides (4895 - 4965 [1135 1204])