what was the articles of confederation?

the answer is: must pay taxes on profits

since it is considered as a part of your income, profits from investments is eligible for tax payment.

the tax from your investment could be influenced by how long you decided to sell it. united states promotes keeping your investment for long term period. so, the tax rate for investments that you sell in less than one year is typically higher compared to investments that you sell in more than one year period.

social contract theory basically says that all individuals are born equal, and provided a god given right to consent to be governed. american government is based of this

thomas hobbes and john locke said that we are selfish, individualistic, and constantly at war with each other, therefore we need to be controlled. 

government is defined as the legitimate use of force to control human behavior within territorial boundaries, here comes in hobbes and locke.

hobbes takes the part about controlling human behavior. while locke takes the part of legitimate use of force, since force is not legitimate unless there is consent of the people. 

there are basically 3 goals of the government: 1) maintain order by protecting life and property. 2) providing public goods, those which are typically not provided by the public sector, such as roads and education. 3) promote equality be it political, opportunist or outcome equality.