So when a mommy lawyer loves a daddy lawyer very much ....
Okay, so we know where people come from, but how about lawyers as a profession?
A lawyer can wear many hats, and there is huge variance between what one lawyer does from another. So let's establish exactly what a lawyer is. According to Black's Law Dictionary, a lawyer is "[s]omeone who, having been licensed to practice law, is qualified to advise people about legal matters, prepare contracts and other legal instruments, and represent people in court."
The definition was not always so narrow, and indeed, the predecessors to lawyers were not required to go to law school, pass the bar, or be licensed at all.
Before lawyers as we know them, there were officials charged with settling disputes and making decisions. Think of kings, wise men, priests, and judges. The Judgment of Solomon is one well-known example—nearly 1,000 years BC—where King Solomon, faced with two prostitutes claiming to be the mother of a child, uncovered the child's true mother by offering to cut the baby in half and give each woman an equal half. One woman (not the mother) was satisfied with this result while another (the true mother) would rather the pretender have the child than allow the child to be killed.
And although with very few exceptions judges today are lawyers, they fulfill quite a different role. While judges decide how the law is going to be applied given a certain set of facts, a lawyer marshals these facts and tries to convince the judge that his result is the most just given the law.
It wasn't until a couple of centuries AD that lawyers as we know them begin to emerge, and we find these ancestors of lawyers in the orators of ancient Greece.
Orators were those who would argue for or against a given case, often on behalf of another. However, there was a rule in Athens that people could not plead cases for others, but the rule was relaxed when the party to a case asked a "friend" for help, in which case the orator—friend or not—would step in and speak on their behalf. At the same time, there was another rule, this one strictly enforced, that forbade these orators from taking a fee for their services. Thus, these "friendly" orators, who undoubtedly were getting paid under the table, had to pretend that they were spending their lives helping all their friends for free with legal matters.
We have to move North to Rome and forward to about 400 AD before we see laws that allow persons to represent others for a fee. It was Emperor Claudius who abolished the rule prohibiting orators from charging a fee, though he did limit the fee to 10,000 sestertii, which may or may not be a lot of money, depending on what a sestertius is worth. From my research, four sestertii are equivalent to one denarius, which was supposed to be the equivalent day's work for an unskilled laborer or common soldier, though in reality a professional soldier would get between 112.5 denarii per year (0.3 per day) to 225 (0.6 per day). 10,000 sestertii is the equivalent of 2,500 denarii, which seems like a lot, though apparently there were complaints at the time that it wasn't much money. I guess no matter how much you make, you still want more.
In any case, it was in Rome in about 400 AD when people could openly, legally, and for a price, represent others in legal matters. Even then, these advocates' arguments were more rhetorical than legal, having been trained in the art of rhetoric rather than the law. Eventually the shift was to arguing the law, and these "jurisconsults" were essentially lawyers, though there still was no regulating body or licensing requirement.
In fact, it wasn't until 1885 that the first written bar exam was developed. That was in Massachusetts. Before that, some states administered an oral exam, and in others there was no formal licensing requirement.
Now, though it differs from state to state, lawyers typically have to graduate from law school, pass a written bar exam, pass a written ethics exam, pass a character and fitness check, and pay a fee. In other words, lawyers as a profession are now grown up!