There is a tension between Smith's earlier work, The Theory of Moral Sentiments, and his magnum opus, The Wealth of Nations, given that the former highlights our need for sympathy as a critical driver for our behavior. In contrast, the former focuses on the importance of self-interest. Reconciling the tension between the two works has been something that has been attempted by various Smith scholars with little success.
Adam Smith's significant contributions and ideas are
The legacy of Adam Smith highlights the benefits of self-interest and the need for free markets.
In the state of nature, the value created belongs to the laborer, the amount being dependent on the quantity of labor that went into "acquiring or producing" the commodity.
In a world where the accumulation of resources is possible (namely in civil society), the entire value created by labor becomes distributed among wages and compensation for the risk undertaken by the employer. But the employer, on his part, doesn't enjoy the profit to its full extent because the owner of the "stock" (capital or land) has to also be compensated. As such, we see land as the third component of the cost of a commodity.
"In the price of the corn, for example, one part pays rent of the landlord, another pays the wages or maintenance of the laborers and laboring cattle employed in producing it, and third pays the profit of the farmer."
"Wages, profit, and rent, are the three original sources of all revenue as well as of all exchangeable value. All other revenue is ultimately derived from some one or other of these."
Public good excludes rent
Fishing is an example where rent does not usually come into the cost of the commodity as it is a public good and thus is not often subject to taxes.
Trade restriction results in a monopoly in the production in the home market which increases the share of labor and capital in said society. But the question Smith poses is whether that allocation of resources is most efficient.
One of the goals of every individual is to maximize their earning potential under the assumption of resource constraints. To do that, he has to "prefer that employment which is most advantageous to society."
"led by an invisible hand to promote an end which was no part of his intention."