One of the best things about hanging out with philosphers is that they remind you of cool stuff you read way too long ago, like this quote from John Stuart Mill’s On Liberty about the harm principle and individual liberty:
“… the sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number is self-defence … the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others.”