Opponents of marijuana legalization often justify prohibition by pointing to studies suggesting that cannabis can significantly harm the developing brains of youths. But legendary guitarist Carlos Santana - who turns 69 today - argues that legalizing marijuana could make kids smarter. Not by letting them smoke it but by investing tax money in educating America's youth.

"I really want us to invest - with grace and wisdom - into the education of young people," he told the Associated Press in 2009. "Legalize marijuana. And take all that money and invest it in teachers and education. And you will see a transformation in America. That is what is going to reignite us."

But he doesn't advocate using cannabis. In fact, he thinks that educating youth would make them see that smoking, drinking and other recreational vices are less fulfilling than spending their time helping others.

"If we would teach in schools the incredible sensation of climax that it feels to be of service to other people - like Mother Teresa, or Desmond Tutu or the Dalai Lama - smoking pot, and drinking tequila, and watching porno or whatever people do, it pales in comparison when you actually wake up to be of service to people," he told CNN in 2009.

However, he isn't opposed to people smoking cannabis, which he insists is different from other banned substances. He also says that governments oppose marijuana because it makes people think.

"Marijuana is not drugs," he told Fusion in 2014. "Mother Nature makes marijuana. Drugs is what man makes in a laboratory. That imprisons man like heroin or cocaine. Anything that man makes, it makes a creature of habit. You know, when you smoke marijuana like Bob Marley, first of all, you start thinking differently. And a lot of the government, they don't want you to think. They want you to be like, 'Yes, masa - no, masa.' "

Check out clips from these interviews - and Santana's mesmerizing performance at Woodstock - below.

Banner image: El Hormiguero / Flickr.com