cannabis fitness
cannabis epistemology
The branch of philosophy known as epistemology is concerned with the what and how of knowledge; that is, what do we know and how do we come to know it? When it comes to knowledge of cannabis, clearly there are two main ways we can come to know and understand the plant. One way is to study cannabis from without, that is, through external examination of the plant via various forms of scientific and scholarly investigation, be it analysis of its chemical components in the laboratory, its effect on humans in clinical trials, or study of its use throughout human history in the library. 
The other way to study cannabis is from within, that is through personal ingestion of the plant for direct ascertainment of its effects. Through this study from the insideone can experience and see for themselves how cannabis affects their consciousness.
Thus, in our study of cannabis we have two complementary methods at our disposal; external study (investigation in the form of chemistry and neuroscience for instance); and internal study, that is, investigating cannabis via examination of its effects on one's own consciousness (as in phenomenology). Importantly, each method of study informs the other. So far as my own study of cannabis, I would say this...