Logical fallacy

In academic writing, composing an argumentative essay starts with personal assumptions, which, however insightful and profound you believe them to be, will have to be proved as convincing conclusions, through:

One
sufficent objective evidence
Two
sound logic

But the problem is, most of us do not provide enough powerful backup for our arguments, while also presenting a logical breakdown. And this essay is going to particularly deal with the undesirable prevalence of logical fallacies in argumentative writing.

"Fallacies are defects that weaken arguments"[1].

I used to be fairly frightened when it comes to logical construction, a process which seemingly requires an exceptional gift in thinking and an impressive linguistic power. Later, I began to discover that writing logically is something that can be achieved with adequate practice. Our arguments are based on premises (statements to present our "sufficent evidence"), which are arranged with the correct approach of argumentation to, ultimately, support and prove our conclusion(s).

Hence the following principles we ought to take special heed of:

"1. Use good premises (ones you have good reason to believe are both true and relevant to the issue at hand)

2. Make sure that your premises provide good support for your conclusion (and not some other conclusion, or no conclusion at all)" [2]

Now, coming to the main point: What are some of the typical logical fallacies that cause the breakdown of argumentation? How do we avoid them?

Hasty generalisation: Arriving hastily at a sweeping conclusion without sufficient proof.

E.g. Li and Zhao are Chinese. They're both studious. Therefore, all Chinese are hard-working students.

The example might be a tad exaggerated. However, rushed-into conclusions like "All Southerners are short", or "All Easterners dare not eat spicy food" are obviously prevalent and a no-no in argumentative writing. One of the strategies to avoid this fallacy is to steer clear of absolutes--all, every, definitely, etc., and base your conclusions upon universally-acknowledged "truths" or soundly-constructed logical patterns, instead of personal observations and experiences, which are generally partial and subjective, thus unreliable.

Appeal to authority: Granted, appealing to authority strengthens argumentation, and impresses readers with the powerful tessellation between the authority and our arguments. However, in some cases, the authority does not 100% apply to what we're trying to get strengthened or proved.

E.g. A student from one of China's top universities once observed:" the homosexual community in the country take on a hyperbola-shaped pattern, abounding in the good ones at the top, and the bad ones at the bottom, with fewer mediocre people in the middle". No matter this is a valid revelation or not, without crediting an authoratative source, it is still a speculation based upon personal observations. "A student from one of China's top universites" is no expert regarding this issue. There are no reliable statistics from official sources to back up the argument. Therefore, the writer is appealing to the wrong authority here.

Strategy to avoid appealing to the wrong authority: select reliable information and experts' opinion, and if necessary, present the whole process of their argumentation.

Weak analogy: the phrase itself is quite self-explanatory. If the two things the writer chooses do not share enough similarities to form an analogy, then it is a weak one.

E.g. The relationship between a teacher and a student is just like that between a boyfriend and a girlfriend. If the boy (compared to the teacher) cannot make the girl happy, then the relationship breaks down. The same goes for a teacher and a student.
Though this sort of relationship between a teacher and a student may be prevalent in certain companies that label themselves as educational institutions, a teahcer-student relationship is by no means the same as one between two lovers.

One thing that can be done to prevent this is to check if the two things being compared share sufficient similarities to form a sound foundation for an analogy.

The above are some of the typical logical fallacies that we commit in academic writing. But through frequent and effective practice, all of them can be avoided.

Reference:
[1], [2]. http://www.unc.edu/depts/wcweb/handouts/fallacies.html