I was reading an article about the recent controversy over prescribing antidepressants for children, and the article in the NY Times said, "But, it said, physicians could continue treating with the proscribed drugs 'if your patient is being successfully treated with any of these products.'"

I began to wonder how "proscribe" came to mean something so different from "prescribe." It comes from the Latin word "pro" meaning "in front" and "scribere" meaning "to write." The dictionaries then seem to take a big leap and go to "to condemn or forbid as harmful or unlawful" as part of the etymology.

How did we get there?

The Latin senses of proscribo have a common thread of 'write up in front of people', so basically 'publish', then more specifically 'advertise' and 'publish outlawry and/or confiscation'.

While prae- overlaps with pro- in the sense 'before', it often or usually has the time sense 'beforehand', so the Latin senses of praescribo are 'write previously', 'write beforehand', 'write at the front or head of'; and this gives various senses which consist of disseminating copies of a prior original: 'command, appoint'; 'dictate, write down'; and the noun praescriptio 'rule, order'.

In the old Wild West the authorities would put up "Wanted" posters:

WANTED DEAD OR ALIVE
Dead-Eye Dick
Mexican Pete

In much the same way, the Roman authorities put up notices giving the names of wanted outlaws. These people were proscribed.

Thanks. That makes a lot of sense.