From Samuel Johnsons dictionary of 1785:
Separation: n. the act of departing; disjunction. 2. The state of being separate, disunion. 4. Divorce, disjunction.
Secession: s. a act of departing
Declaration of Independence:
"When in the Course of human events it becomes necessary for one people to dissolve the political bands which have connected them with another and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation."
And again:
"We must, therefore, acquiesce in the necessity, which denounces our Separation, and hold them, as we hold the rest of mankind, Enemies in War, in Peace Friends.
Without the "opinion" of an inconsistent Madison...what's the distinction between the words secession and separation by the body-politic in the Declaration viewed through the lens of Natural Law and laws ordained by our Creator referenced in the document? In your own words please.