The Cannabis Debate: The Strongest Arguments For and Against Legalization

More than any other drug, cannabis is the topic of serious debate. Barely anyone is going to seriously sit in front of you and pontificate on the virtues of cocaine for society, but people are opposed to the criminalization of marijuana on much stronger grounds.

This passion from advocates is met with equally strong statements from those who feel that marijuana use is undermining society, addicting young people and leading users to harder drugs or even crime.

If you’re unsure which side you identify more with, or want to understand why people support or oppose cannabis, we’ve collected the best arguments from both sides here, along with the evidence backing them up.

As well as a quick run-down in this post, each specific point is expanded in more detail in a separate post.

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Arguments Supporting Legalization

1. Smoking Cannabis Is a Personal Freedom, and Doesn’t Harm Others

Key Points

• John Stuart Mill’s “harm principle” asserts that people should be free to do whatever they want unless it harms another person. “Your freedom to swing your fist ends where my nose begins.”
• Marijuana use, through edibles or smoking either privately or in an open outdoor space, doesn’t harm others.
• In most cases, marijuana use only affects the users themselves, and so shouldn’t be subject to legal punishment. In short: why should anybody else care?

Counterpoints

• Harm shouldn’t necessarily be defined so strictly. Is a mother not harmed by seeing her child waste opportunities because he or she decides to smoke cannabis and play video games instead? 
• Widespread cannabis use causes societal harm. It is unreasonable to judge a behavior purely on individualistic grounds because we exist in societies and our actions impact our societies. 
• Of course, it’s possible to use cannabis in a way that minimizes harm. But many people also use cannabis in a dangerous way, whether through exposing others to smoke or by irresponsible behavior like driving while high.

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2. Legalizing Cannabis Brings Economic Benefits and Raises Tons of Tax Money

Key Points

• Legalizing cannabis benefits the economy by bringing in tax revenues and by creating business and employment opportunities.
• Colorado and Washington, for instance, collected $423 and $559.5 million, respectively, in tax revenue in 2021.
• For all legal cannabis sales in the US, states took $3.7 billion in tax revenue in 2021, and the cumulative total from 2017 to 2025 is estimated to reach $106 billion.
• Although other economic benefits might be small relative to the size of the economy, Colorado’s industry employed over 41,600 in 2021, for instance.

Counterpoints

• People would buy cocaine from legal stores if it was available and it would of course generate tax revenue. Does this mean we should also legalize cocaine? Finances are not everything.
• Such analyses never consider increased costs in other areas – like possible increases in addiction, mental health care and traffic accidents – and how they impact the financial benefits.
• Revenue from cannabis is generally small relative to the overall size of an economy, and so substantial economic improvement is not likely from legalization alone.

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3. Enforcing Criminal Laws Against Cannabis Is Expensive and Problematic

Key Points

• It’s expensive to prosecute people for marijuana, and in practice there is almost always a racial bias. And for what benefit, exactly?
• The US would save at least $7.7 billion on enforcement if marijuana was legalized nationwide, based on analysis conducted before any states legalized.
• Black people are 3.64 times more likely to be arrested for marijuana possession, despite using at similar rates to white people (actually at slightly lower rates, as of 2018).
• While legalization doesn’t fully rectify this disparity, it’s clear that the war on drugs disproportionately affects non-white communities.

Counterpoints

• Marijuana enforcement costs don’t end with legalization. Every legal state has possession limits, requirements for selling (and punishments for unauthorized sales), bans on driving high and more. These must also be enforced, so all of these problems would persist to some degree.
• It obviously costs money to enforce the law. This is not a sufficient argument for removing the law. If marijuana is dangerous, the cost is arguably justified.

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4. Cannabis Is Safer Than Alcohol (and Most Other Drugs)

Key Points

• Cannabis is safer than alcohol. 140,000 Americans died from drinking from 2015 to 2019, compared to a literal few – potential, not confirmed – deaths from cannabis.
• Based on “margin of exposure” analysis, alcohol sits with cocaine and heroin in the “high risk” category while marijuana is “low risk.”
• If the deadly, high risk product is OK with society, what possible reason could there be for banning low risk, rarely (if ever) fatal cannabis?

Counterpoints

• Death is not the only negative consequence possible from cannabis use, so focusing on it ignores many valid concerns. 
• Drug law is not and should not be purely based on personal risks to users. The risks to society are also important, and legalizing marijuana may falsely send the message that marijuana is safe. 
• If cannabis is safer than alcohol, this doesn’t mean cannabis should be legal. Perhaps, instead, alcohol should simply be banned too. 

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5. Cannabis Has Many Medical Benefits

Key Points

• 37 states, three territories and D.C. allow medical marijuana, for conditions such as chronic pain, nausea, glaucoma, PTSD and many others.
• This clearly contradicts the classification of marijuana as a Schedule I controlled substance.
• Moreover, if marijuana helps someone with chronic pain, for instance, and he or she uses responsibly, what is the justification for restricting access?
• Purely medical marijuana laws may enable states to meet this need, but this creates a two-tier system where one citizen can possess marijuana while another can’t.

Counterpoints

• The evidence for marijuana helping many of the listed conditions is mixed at best. The FDA has approved some marijuana medicines for limited purposes, and these are the only ones which are valid medical treatments. 
• Some people having a medical need for marijuana does not mean anybody should be able to consume it. Many drugs are available medically but not recreationally, such as oxycodone. 
• The push for medical marijuana is a wedge issue, bringing well-meaning people over to begrudging acceptance of something else entirely, recreational use.

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Arguments Opposing Legalization

1. Cannabis Is a Dangerous and Addictive Drug

Key Points

• Although cannabis isn’t as dangerous or addictive as other drugs, it is still dangerous and addictive.
• Smoking marijuana exposes users to many of the same chemicals as tobacco smoke and has negative effects on the respiratory system.
• Cannabis can trigger and worsen schizophrenia, and negatively affects people with anxiety and mood disorders.
• Around 9% of cannabis users become addicted, as well as 17% of people who started using as teens.
• Of people who use cannabis every day, researchers estimate that between 25 and 50% are addicted.
• With all of these risks, how can we sanction or even encourage people to partake?

Counterpoints

• The fact that cannabis isn’t as dangerous or addictive as other drugs is exactly why we should legalize. We accept the (larger) risks of alcohol, so why is weed still illegal?
• Smoking cannabis is less dangerous to users than smoking tobacco.
• People with schizophrenia or risk factors should avoid marijuana, but that doesn’t mean that adults with no mental health problems should. Some people have medical reasons for avoiding caffeine, but it doesn’t mean it should be banned. 

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2. Legalizing Cannabis Use Is Bad for Society

Key Points

• Legalizing cannabis leads to negative societal outcomes, in particular in terms of widespread use and people driving high.
• Cannabis use increases when it’s legalized. Based on a study of twins in different states, legalization makes people use weed 20% more than they would otherwise.
• If cannabis is dangerous and addictive, this is a very bad thing. More use means more risk.
• Although driving while high isn’t as bad as driving drunk, it still increases your risk of an accident.
• Studies have mixed results but one example shows a 6.5% increase in accidents causing injury after legalization, and a 2.3% increase in fatal crashes.
• We could be moving towards a Brave New World in which addiction is normalized and stoned driving accidents are seen as the acceptable price for our “freedom.”

Counterpoints

• Cannabis use increases when it’s legalized because people want to use it. This isn’t a bad thing just because you don’t want them to. The question is whether these people should be considered criminals, not whether you like it.
• There is no state, nor advocate, who claims we should be able to drive high. People will do it, but people do it anyway. We need to enforce these important laws to save people’s lives, not prohibit the whole substance just in case. 
• Legalization also has positive impacts for society, as mentioned above. Focusing purely on the negatives is dishonest. 

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3. Cannabis Is a Gateway Drug

Key Points

• A hypothesis from the 1970s asserts that there is an “invariant sequence” for first-time drug users: alcohol/tobacco, to cannabis, and then to “harder” drugs.
• Therefore, marijuana is a key step on the path to dangerous drug use, so encouraging it would bring significant risks.
• In future research, the same author found that even after controlling for adolescent behavior, peer group influences and mental health, cannabis use still predicted progression to other drug use.
• There are some potential mechanisms for gateway effects too. Nicotine exposure has been shown to encourage mice to self-administer cocaine.
• Researchers also pointed out that using one drug “may remove the fear and perceived risk associated with the use of other drugs” and thus encourage experimentation.

Counterpoints

• Data for this argument is lacking. While many people do follow the progression, most marijuana users don’t go on to use harder drugs, and the “invariant progression” is culturally biased to the US, and essentially absent in countries like Japan.
• Alternative explanations depend on common factors (such as psychological differences) that may explain both the cannabis use and the harder drug use.
• The entire idea that weed is a “gateway” is borne of an implicit understanding that it isn’t that dangerous on its own. Without a legitimate argument, people were left to claim that stoners would graduate to heroin and then talk about how bad that would be. It is primarily a rhetorical trick, not a factual argument.

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4. Black Markets Still Exist in a Legal System

Key Points

• Advocates of marijuana often argue that legalization will kill the black market, but cases like California show that this isn’t always true.
• According to Leafly’s “Opt Out Report,” 55% of cannabis sales in California and 80% in New Jersey are through the black/gray market.
• If a city doesn’t vote for legal weed, either states have to force them to have dispensaries, or black market sellers will capitalize.
• If anything, legal weed makes it easier for illicit sellers because cops can’t stop people for simple possession.  
• And illicit sales carry all of the usual downsides. Legalization advocates claim it will help stop sales to youth, for example, because dispensaries can check ID. But with a strong black market still operating, this goal is not achieved. 

Counterpoints

• Black markets persist in legal systems when there is insufficient coverage of dispensaries. The solution to black markets is still widely available legal cannabis. Some states not providing this doesn’t show legalization doesn’t work. 
• There are black markets in illegal states too. So the worst case scenario for legalization is actually the current status quo, which this argument is apparently defending.
• Some people will always try to make money illegally, whether it’s selling counterfeit cigarettes or setting up a gray market weed stall. The fact that they exist doesn’t mean we should keep marijuana illegal.

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5. Cannabis Is Dangerous for Youth

Key Points

• Young people are particularly at risk from cannabis use.
• Weekly marijuana use increases the risk of anxiety, depression and suicide attempts. A meta-analysis found that the risk of depression increased 37% and the risk of suicidal ideation increased 50% in marijuana users, relative to non-users.
• Teens who use marijuana are more likely to get addicted, with 17% being addicted compared to 9% of marijuana users overall.
• The risks of psychosis and schizophrenia are largest for young users.
• Some studies suggest an IQ decline for teen stoners, but there are contradictory findings that make conclusions hard to draw.
• If legalizing weed increases teen use, there could be many unintended consequences because of these points.

Counterpoints

• Young people are at risk from cannabis, and this is why we should regulate and control the market to make it harder for them to access it. Street dealers don’t check IDs.
• Again, potential risks to some groups doesn’t mean no group should have access. Alcohol and tobacco are also particularly dangerous to youth, but we minimize the risk that they get access, not ban the substances. 

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How We Produced This List

Coming up with a list of the best and most common arguments for and against cannabis is not a simple matter. Different people have different views and different arguments that appeal to them.

However, there are some points that are made more frequently than others, and ones that resonate with people more. A 2019 Gallup poll asked 1,017 American adults (aged 18 or over) whether they favor or oppose legalizing marijuana and why, with 633 being in favor and 364 being opposed. The most commonly-cited reasons were prioritized for this list, supplemented by other online sources where people make arguments for and against legalization. 

The arguments themselves also haven’t been repeated verbatim. Each argument rests on some claims, and these claims were investigated based on available evidence.

Where possible, we used peer-reviewed scientific evidence to back up or refute claims. Where not possible or not applicable, we used appropriate non peer-reviewed sources. If some element of the original claim was incorrect or unproven, we either explicitly stated this or simply made the best possible version of the original argument (we made a “steel man” argument). 

It’s also crucial to note that not all sources are equally valid, even if they are peer-reviewed. With this in mind, we’ve included some brief information about each source and comments on its validity. For example, a self-reported study with 15 participants is better than what an unknown author wrote on his blog, but much worse than a randomized controlled trial or large cohort study.

The overall aim, as always, was to provide an objective look at the topic to the best of our ability. 

Conclusion

We aren’t here to tell you what to think about marijuana. People have personal reasons for liking and disliking something, and just like whom you choose to support politically, there must be a degree of acceptance that other people don’t see issues in the same way you (or we) do.

However, understanding both points of view and the evidence that supports (or contradicts) them is a vital step towards understanding the impact cannabis has on society, and why the debate around the topic is still so active and heated.