What is Critical Thinking?
What About Assumptions?
Assumptions are beliefs or ideas that are believed to be true without proof or evidence and are used to support reasoning. This lack of verification can create bias when thinking critically. Like any human activity, the practice of critical thinking requires several basic assumptions to make sense. For people who don’t share these assumptions, the whole process can be experienced as confusing or nonsensical. Here is a partial list of assumptions that sometimes cause trouble for people new to critical thinking.
- Critical thinking (CT) is evaluative. An evaluation is a statement that compares what is the case to a standard about how things
should be. CT requires people to make lots of judgments about good and bad, right and wrong, what we should or shouldn’t do. The standard of evaluation used in critical thinking for reasoning is reliability. Good reasoning is reliable, and bad reasoning is unreliable. - In CT, reasoning implies evaluation, both individual (“You should recycle your aluminum!”) and collective (“We should abolish the death penalty!”). Each statement can be supported by reasons, and the reasons can be evaluated as better or worse. Although this should not be confused with opinions or facts.
- In CT, “Truth is what is so about something, the reality of the matter, as distinguished from what people wish were so, believe to be so, or assert to be so” (Ruggiero, 2015, p. 25)
- When using critical thinking you should not contradict yourself. Contradictory statements, by definition, cannot all be true, and based on #3 above that means they can’t be partly true, or true to some people but not others.
- Critical thinking requires judging other people’s opinions (along with our own!) – not in isolation, but in relation to each other.
Many people put the majority of their critical thinking energy into judging the thinking of those they disagree with (fast thinking). Our hope is that you will have come to understand that thinking carefully about your own beliefs is worth more of your time, and that you will have come to appreciate the vital importance of people who do not share your same ideas to your process of slow thinking.
Check Your Knowledge: Assumptions
Read the following statements and then determine the assumption.
The U.S. is overreacting to the growth of AI. Technology is meant to be utilized to its fullest.
“Eating healthy is important. Doctors and physical fitness advisors tell you about the advantages of health foods. Then why are these foods so expensive? Companies that sell these foods are raising prices for simple things such as fruits and vegetables….People want to be healthy but it seems that corporate America really doesn’t want to make that prospect cheap. You should avoid wasting money just to eat healthy; go buy cheap frozen vegetables at the grocery store.” (Browne & Keeley, 2018, p.56)
Taking an act or statement for granted (Merriam-Webster Online)
Judgements about good or bad, right or wrong
Evaluations for better or worse
A view or judgement
Something known or proven true
False statement
