Food of the Gods: The Search for the Original Tree of Knowledge : A Radical History of Plants, Drugs, and Human Evolution

If you look hard enough you can find anything you want. In food of the gods, the author finds hallucinogenic mushrooms are the key point to the evolution of men. Hallucinogens are also a key component of a female-based partnership society. (Thus they are condemned by domineering, male-based society.) He sees the drugs as an important step that helped humans to progress from being "mere apes" to the higher intelligence they have today. Some cultures in the Amazon are able to hold on this "shaman" culture. He is enamored with the drug induced states and would love for society to have a greater respect for plants and psychoactive states they can provide.
He criticizes the drug policy of today for not performing more research into positive uses of drugs. This does seem to be a valid concern. However, he takes it further. Much further. For him drug policy is a means by which the male "dominate" group can assert their dominance over the female partnership society. Drug policy is how those in power stay in power. They pick drugs that they like and restrict other drugs so that they can get a cut of the revenue from them. 

His theories (such as "stoned ape" evolution do tend to be extreme. However, when the book does venture away from theory, it has some interesting content. A section describes the "drug history" of the world. The new world had a lot more available drugs than the old world. Some drugs like alcohol and tobacco assumed a regular place in civilized society. Others, including marijuana and heroine were shunned. Others, such as coffee, chocolate and sugar are not even considered to be drugs, yet they have significant psychoactive impact on humans. It is an interesting read that tries to make sense of the way that drugs have evolved to be placed in different buckets in our culture. It almost makes up for the extremeness of the general theories of hallucinogenics being the source of most human advancement.