On Poisons

One important discussion John Stuart Mill brings up in his analysis of liberty is the sale of poisons and the legitimate control that can be placed upon it. According to Mill:

If a public authority, or even a private person, sees any one evidently preparing to commit a crime, they are not bound to look on inactive until the crime is committed, but may interfere to prevent it. If poisons were never bought or used for any purpose except the commission of murder, it would be right to prohibit their manufacture and sale. 

Mill further states:

Again, it is a proper office of public authority to guard against accidents. If either a public officer or any one else saw a person attempting to cross a bridge which had been ascertained to be unsafe, and there were no time to warn him of his danger, they might seize him and turn him back without any infringement of his liberty; for liberty consists in doing what one desires, and he does not desire to fall into the river. Nevertheless, when there is not a certainty, but only a danger of mischief, no one but the person himself can judge of the sufficiency of the motive which may prompt him to incur the risk: in this case, therefore, (unless he is a child, or delirious, or in some state of excitement or absorption incompatible with the full use of the reflecting faculty,) he ought, I conceive, to be only warned of the danger; not forcibly prevented from exposing himself to it.

This presents us with an interesting dilemma. Mill makes it obvious in the first passage that he disagrees with the prohibition of the sale of poisons. However, in the second passage he elaborates with an example of the unsafe bridge which makes it clear that Mill believes in preventing harm (in this case, to oneself). What if consuming a poison would cause physical or mental harm (which it probably does)? Wouldn't it be correct to forcibly prevent a person from exposing himself to it? Mill leads us to believe with his example of the unsafe bridge that the person crossing the bridge should be warned and should only be forcibly prevented when there is not enough time. However, I argue, that the person should be forcibly prevented even after being warned. Furthermore, I believe the logic that brought me to this conclusion is evident in Mill's writing.

Mill mentions that liberty consists in doing what one desires, but the person who is about to cross the bridge does not desire to fall into the river and therefore, we may forcibly prevent him from crossing. From that example, I think it is fair to ask if any one desires to be addicted to a poison and to ruin his life (I am limiting this argument within the parameters of addictive poisons). True that it isn't for certain that a person would become addicted and that he would ruin his life, but it is a considerable risk; even in Mill's example, it is not for sure that the bridge will collapse, it is just deemed to be unsafe. Therefore, I believe it is right to prevent a person from consuming dangerous poisons.

Mill also believes that force should be implemented only towards a person who is in some way unable to think clearly. But I ask, what if that person is thinking clearly and just does not believe the warnings? What if that person does not believe that the bridge will collapse? I believe he should be prevented from committing the act anyway. As long as there is a considerable risk of a person killing himself or even ruining his life (assuming he does not desire these things), he should not only be warned of the dangers but also prevented from taking the risks.

Thus, in the case of the manufacture and sale of considerably dangerous poisons, I am of the opinion that they should be prohibited. However, as a necessity, scientific research should be conducted to determine which poisons belong in this category. I am in no way able to present a viable method nor an applicable standard to determine and categorize dangerous poisons.