Difference between "assent" and "consent"

To consent is to give permission, which could have been withheld. It implies a power relationship where the consent is granted by the party with more power.

There is the political theory that says, governments can rule only with the consent of the governed. That is, the people consent to be governed and thus grant their power to the government.

To assent is to agree with a statement made by an equal. On the Supreme Court, one justice writes the opinion of the majority, to which other justices assent. Those that disagree are said to dissent, that is to disagree.

So, consent = permission while assent = agreement. A subtle distinction perhaps, but a useful one.

My brain's immediate shorthand response is:

"assent" = "agree"

"consent" = "allow"