Analysis of the mechanisms underlying the clinical effects of different drugs is a vital part of psychopharmacology. It is fair to say, however, that such analyses have thus far met with little success. This lack of success can be traced to a variety of sources that have flawed the analytical process itself. Detailed examination of these sources not only illuminates the nature of the flaws they engender, but suggests ways in which the analytic process can be modified so as to be a more fruitful one.