Extremely short argument: I have read Against Intellectual Monopoly, and found the arguments compelling (I trust there were no major factual inaccuracy).
They cite examples of industries that have prospered without patent protection.
Outside of pharma, the pro-patent position seems quite weak. And even for pharma there may be better models (lotteries, bounties for drugs, public funding)
I guessed that would come up :-) Unfortunately, that book contains many fabrications and mischaracterizations of other work, which calls into question anything they say. A previous comment pointing this out:
http://www.dklevine.com/general/intellectual/against.htm