The "Philosopher's Drug" is the metaphorical drug that affects the mind of those that are philosophical or psychologically analytic. The drug cannot be induced by any means that a regular drug could. The drug is stored within philosophers' cerebral cortex (a part of the brain that partakes in the process of reasoning and logic).
The stored drug is then released between the times 9:00 PM - 12:00 AM. The drug enhances philosophers' ability to reason and allow them to trudge through the most unrealistic debates. The drug wears off at 12:00 AM due to lack of resources. The cerebral cortex then begins to regenerate and store "the Philosopher's Drug" for the next 21 hours, before releasing it in the philosophers' blood stream for another (approximate) three hours the next night.
The Philosopher's Drug only applies to those who are considered philosophical. There is no "self-diagnosis" to having or not having this drug. It takes another mind to determine whether your cerebral cortex produces the drug or not. Once determined, the decision is final.
Mark, stop talking about all this "new age of enlightenment" crap, it's the philosopher's drug kicking in.