So long as we retain the enormous disparity between the legal treatment of alcohol and that of marijuana, the cost of the marijuana laws in alienating the young and in interfering with drug education will not decrease. Finally, since it is impossible to draw any moral distinction between alcohol and marijuana, the only acceptable distinction between the drugs would be a practical one. The problem, however, is that exactly the same is true of marijuana. Finally, insofar as the argument assumes that the damage caused by alcohol and marijuana would be completely additive, it is probably wrong. To some extent increased marijuana use may displace the use of alcohol, and at lease some alcoholics have improved physically and mentally on making the substitution.
Cannabis is less harmful than alcohol.
The costs of cannabis prohibition are greater than the benefits.