Jason Pontin has written a perceptive analysis of a timeless question:  what changes in law need to be adopted in order to account for technological advances (see “Free Speech in the Era of Its Technological Amplification”)? In answering that question, he takes the right approach by taking up John Stuart Mill’s harm principle, which at its core makes this claim:

“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-protection … 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. His own good, either physical or moral, is not a sufficient warrant.”

This principle is both profound and incomplete. The last sentence announces a strong antipaternalist manifesto that no government, individual, or group should be able to reform the private preferences of other individuals. That principle is a welcome recipe for social peace: if the rule were otherwise, it would be necessary to decide which individuals or groups occupied the dominant position with respect to other groups. Any interested group would find it most difficult to choose on neutral principles which group should have that preferred position. In contrast, a principle of parity works as well for large and fractured societies as it does for smaller and coherent ones, by making that question irrelevant. Score one for Mill.

Mill does less well, however, in defining how the harm principle works. One possible implication of this principle is, as Pontin notes:

The only principle I can imagine working is yours, where “harm” is interpreted to mean physical or commercial injury but excludes personal, religious, or ideological offense.

Read more at MIT Technology Review