Because medicines have healing or minimizing the negative effects of an illness or an injury as their end, they are good for the human person even if they have deleterious side effects. Thus, chemotherapy to treat a cancer is justifiable by the principle of double effect even if it leads to the foreseen but unintended detrimental consequences of nausea, hair loss, and fatigue (Cataldo 1995). This essay does not address or evaluate the legitimacy of the medical use of marijuana. We note, however, that there are significant blurred boundaries between medical and recreational uses: multiple studies have found that those who used marijuana for purported medical reasons also used it for recreational reasons (Ware et al. 2005; O'Connell and Bou-Matar 2007; Reinarman et al. 2011; Bostwick 2012). Furthermore, patients without recreational experience of marijuana have trouble tolerating its psychoactive effects and often reject continued medical use

The use of marijuana in dealing with emotional issues whether through medical prescription or for recreation contradicts Kant’s formula on morality. It states that one’s dignity ought not to be compromised even in the face of overall utility. Through the subtext of the categorical imperative, Kant continues to state that if a person destroys his body in an effort to escape from a difficult life situation, the person is merely using his "person" as a means.

If you want to send your money to people less well-off, by all means that is your right. But it is certainly not your duty to do so.

Fulfilling yourself as an individual requires putting your own needs and interests first.

This argument equates ethics with the pursuit of self-interest, so that whether you happen to defend acting ethically or not, you are still always defending acting in a self-interested way.

For example, even though at times refraining from lying is really in my own best interest, since it helps to maintain trust between myself and others upon whom I rely to tell me the truth, this is not always the case.

In other words we are more generous with ourselves in terms of getting ourselves off the hook — it’s not my fault it’s the situation I was in — than we are with others — clearly it is their fault!

Many examples of this can be found in the marketplace. The notorious “bait and switch” tactic relies on this bias.

Appealing to authority is a commonly used way of trying to convince people. But why do we find authorities believable in the first place? Because they are authorities? In this case we may wonder why they are considered authorities at all.

we were all already adept at persuading others by manipulating logic for the sake of convincing others that we were right and hence asserting social dominance, whether or not our claims were truly justified.

Understanding the logic of arguments, if nothing else, should encourage us to be a little more modest in our claims to knowledge.

So when we are looking at arguments we are deliberately ignoring the many other ways we can use language, such as asking questions, making commands, expressing feelings

Too often this word conjures up a pointless verbal fight between people with opposed views. They argue rather than discuss because their differences of opinion are fixed in place and neither will budge. It is typically a good idea to stay away from arguments in this sense.

Even though, as I have been emphasizing, we all have the capacity to reflect on our lives and choices, we do not always spend the time or make the effort to do this carefully and deeply. This is because we are mostly preoccupied with the immediately practical details of our lives.