Negative law is expressed as "thou shalt not" terms. A lot of the bible is "negative law" and telling people what they can't do. It's purpose is to set boundaries and rule those boundaries with measurements and punishments. Thou shalt not steal is defined in hundreds of more detailed laws from laws against shoplifting to unenforced laws against banks swindling people out of billions.
Positive laws are expressed as "thou shall". The bibles "Thou shall love thy neighbor as thyself." Positive laws start with setting goal posts and then work to define the requirements for virtue and good function. Positive laws define both the good and the means for attain the goood. Our laws for creating corporations are an example of positive law, implied by the requirements within the constitution:
“The power of creating a corporation, though appertaining to sovereignty, is not, like the power of making war or levying taxes or of regulating commerce, a great substantive and independent power which cannot be implied as incidental to other powers or used as a means of executing them. It is never the end for which other powers are exercised, but a means by which other objects are accomplished. No contributions are made to charity for the sake of an incorporation, but a corporation is created to administer the charity; no seminary of learning is instituted in order to be incorporated, but the corporate character is conferred to subserve the purposes of education. No city was ever built with the sole object of being incorporated, but is incorporated as affording the best means of being well governed. The power of creating a corporation is never used for its own sake, but for the purpose of effecting something else. No sufficient reason is therefore perceived why it may not pass as incidental to those powers which are expressly given if it be a direct mode of executing them.” [McCulloch vs Maryland]
A society cannot survive without both positive law and negative law. Negative laws keep people within their swim lanes, out of each other's hair and keep them from killing people. Positive law through it's implied power defines what civilizations should look like, how they should provide for the common good, and what it takes to attain that good. They then establish and insititutionalize organizations and give them the resources to accomplish that good.