There is, therefore, no necessity to look out of Greece for the establishment of servitude in that country by conquest and war. But the peaceful colonization of foreign settlers would (as we have seen) lead to it by slower and more gentle degrees. And the piracies of the Phoenicians, which embraced the human species as an article of their market, would be an example, more prevalent and constant than their own, to the piracies of the early Greeks. The custom of servitude, thus commenced, is soon fed by new sources. Prisoners of war are enslaved, or, at the will of the victor, exchanged as an article of commerce. Before the interchange of money, we have numerous instances of the barter of prisoners for food and arms. And as money became the medium of trade, so slaves became a regular article of sale and purchase. Hence the origin of the slave-market. Luxury increasing slaves were purchased not merely for the purposes of labour, but of pleasure. The accomplished musician of the beautiful virgin was an article of taste or a victim of passion. Thus, what it was the tendency of barbarism to originate, it became the tendency of civilization to increase. Slavery, then, originated first in conquest and war, piracy, or colonization: secondly, in purchase. There were two other and subordinate sources of the institution--the first was crime, the second poverty. If a free citizen committed a heinous offence, he could be degraded into a slave--if he were unable to pay his debts, the creditor could claim his person. Incarceration is merely a remnant and substitute of servitude. The two latter sources failed as nations became more free. But in Attica it was not till the time of Solon, several centuries after the institution of slavery at Athens, that the right of the creditor to the personal services of the debtor was formally abolished. A view of the moral effects of slavery--of the condition of the slaves at Athens--of the advantages of the system and its evils--of the light in which it was regarded by the ancients themselves, other and more fitting opportunities will present to us.