What is critical thinking?
Its definition describes what writers do

Students must be taught to be critical thinkers and those of us involved in teaching writing must help.

Once you understand the definition of critical thinking, you will find it easy to see that teaching writing is a superb way of teaching critical thinking skills.

Definition of critical thinking: NOT!

The most common American English meaning of the word critical means having a tendency to find fault. However, as you know, words frequently have more than one meaning. When a word has more than one meaning, its meaning must be deterimed from the depends on the context in which it is used.

An examination of sentences in which the word critical is paired with the word thinking, reveals that critical thinking refers to something positive or desirable. So you go back to your dictionary to look for another meaning of critical does not refer to something bad or negative.

(Incidentally, analyzing words in context is a criticial thinking strategy used for developing vocabulary for reading comprehension and writing.)

A second definition of critical means characterized by careful analysis and judgment. When we ask what is critical thinking, it is this second definition of critical that is used.

The "dictionary definition" of critical thinking, then, is thinking that is analytical and evaluative, the kinds of higher level thinking of Bloom's taxonomy. Critical thinking boils down to making decisions on a logical rather than an emotional basis.

What is critical thinking by writers?

The expository writing process consists of a series of logical decisions. Some of the specific ways writers think critically to make those decisions are:

• They ask questions to clarify their understanding.

• They determine what information they have and what they lack.

• They seek evidence to support opinions.

• They have strategies that allow them to be thorough and efficient in their thinking-writing.

• They reject irrelevant information.

• They test a working thesis by examining evidence and adjust their thesis as that evidence demands.

• They self-assess their writing process and products.

I could expand the list, but I think you can see that expository writing involves critical thinking and that critical thinking can be fostered through writing.