Robert Hooke, one of the greatest scientists/inventors ever, used cannabis way back in the 17th century. He considered marijuana as a reason for laughter, not fear:
He [Robert Hooke] was possibly the most inventive person who ever lived . . . . Hooke discovered the cell by looking at a piece of cork with one of his own inventions – the compound microscope. He anticipated aspects of Darwin’s theory of evolution by almost 200 years. Hooke also improved the telescope. The drawings he made of the astronomical bodies he observed attest to his uncanny precision. After the great fire destroyed Central London in 1666, Hooke partnered with the architect Christopher Wren to redesign and rebuild the city. Hooke was the foremost experimentalist of his age. Using coiled springs, he derived the Law of Elasticity, known today as Hooke’s Law. He perfected the air pump, the height of technology in its time, and used it to experiment on respiration and sound. And he experimented with cannabis. He reported to a meeting of the Royal Society that a sea captain friend of his “had so often experimented with it that there is no cause of fear though possibly there may be of laughter.”
This quote comes from Neil deGrasse Tyson on Cosmos.
Science, it does cannabis legalization good.