The fallacy of division, also known as “false deduction”, is a type of informal fallacy which occurs when the arguer mistakenly concludes that something is true to one or some of the parts of the whole simply because it is true of the whole.
As we can see, the fallacy of division is the opposite of the fallacy of composition; as we may already know, the fallacy of composition is committed when the arguer erroneously assumes that something is true to the whole simply because it is true to some of the parts of the whole.
Let us consider the example below.
Example 1
One of the causes of poverty is laziness. Since 80 percent of the Filipino people are poor, then it can be logically argued that the Filipino people are lazy.
As we can see in the example above, the specific characteristic of the group as a whole (that is, the laziness of the Filipino people) is mistakenly attributed to all the members of the group (that is, the Filipino people are lazy). As the example illustrates, many Filipinos may have the characteristic of being lazy, which may be one of the causes of poverty. However, it is not safe to assume that the characteristic of being lazy is possessed by all the Filipino people taken individually. Thus, again, what is true of the whole is not necessarily true of the parts.
The examples below will further illustrate the nature and dynamics of the fallacy of division.
Example 2
The union voted to strike. Thus, every member of the union voted to strike.
Example 3
Humans are the only animals capable of philosophical thinking. Thus, every person is capable of philosophical thinking.
Example 4
Tomatoes are common in California. Therefore, since Los Angeles is in California, tomatoes are common in Los Angeles.
Example 5
The average beginning salary of college graduates with a major in nursing is USD 90, 000 per annum. Therefore, if I major in nursing, I can expect to begin at USD 90, 000.