[robertpaulsen]

Well, let's see. Off the top of my head, I can come up with 8 rational criteria:

1) Its actual or relative potential for abuse.
(2) Scientific evidence of its pharmacological effect, if known.
(3) The state of current scientific knowledge regarding the drug or other substance.
(4) Its history and current pattern of abuse.
(5) The scope, duration, and significance of abuse.
(6) What, if any, risk there is to the public health.
(7) Its psychic or physiological dependence liability.
(8) Whether the substance is an immediate precursor of a substance already controlled.

[MrLeRoy]

Several of your criteria are plausible. As for dependence/abuse (1, 4, 5, 7), Institute of Medicine figures show that of all those who have ever used marijuana, 9% became dependent, while the corresponding figure for alcohol is 15%.

(2) Scientific evidence of its pharmacological effect, if known.
(3) The state of current scientific knowledge regarding the drug or other substance.

These are ill-defined; WHAT must be known about a substance and its pharmacological effect to justify criminalization?

(6) What, if any, risk there is to the public health.

It's not clear to me that the use of any drug poses a risk to the public health; do you have any examples?

[tacticalogic]

1) Its actual or relative potential for abuse.
(2) Scientific evidence of its pharmacological effect, if known.
(3) The state of current scientific knowledge regarding the drug or other substance.
(4) Its history and current pattern of abuse.
(5) The scope, duration, and significance of abuse.
(6) What, if any, risk there is to the public health.
(7) Its psychic or physiological dependence liability.
(8) Whether the substance is an immediate precursor of a substance already controlled.

Maybe we should have one of those "blue ribbon commissions" to get all the evidence together, study it, and make a recommendation. Wait... we already did that.

[MrLeRoy]

Off the top of my head, I can come up with 8 rational criteria:

That's not off the top of your head---that's merely a crib from the Controlled Substances Act (Part B §811(c))! No wonder 2 and 3 weren't actually criteria. And here I thought you were actually thinking about the subject.