Dr. Matthew Paldy

Psychotherapy and The Mind: Critical Thinking, Knowledge, and the Scientific Method

By Matthew Paldy, PhD, LP

Uncritical Thinking

For centuries, people based their beliefs on their interpretations of what they saw going on in the world around them without testing their ideas to determine the validity of these theories — in other words, they didn’t use the scientific method to arrive at answers to their questions Rather, their conclusions were based on untested observations, popular belief, or speculation.

Beginning with Hippocrates in 300 BC until the advent of modern medical research in the nineteenth century, most doctors believed that illness resulted from an imbalance of four fluids, called "humours," in the body: blood, phlegm, black bile, and yellow bile.

It was believed that different foods produced different humours within the body. For exmaple, warm foods tended to produce yellow bile while cold foods tended to produce it's opposite, phlegm. Medical treatments focused on correcting imbalances in these humours. A person suffering from an excess of one humour would be served a food associated with the opposite humour. For example, a person who was coughing up phlegm was served wine, which was thought to produce yellow bile. It was also believed that these humours gave off vapors which ascended to the brain and that an individual's personality characteristics were determined by the state of that person's humours.

Even today, the remnants of Hippocrates' four humours persists, especially in astrology and alternative health cures, where they are believed to determine personality, health, and happiness. It was also believed that the four seasons of the year could affect the health of a patient. Many medieval physicians used astrology as part of their treatment, believing that the movements of the moon and stars affected when a cure was most effective. These beliefs still persist today in many astrological circles. For example, many people claim that a full moon affects their health, despite no scientific evidence to support this. What is actually happening is that the person knows it is a full moon and this unconsciously affects their feelings and behavior.

Methods of "Knowing" Something

Why were these absurd beliefs so widely adopted in medieval societies? We can understand this question by examining the nature of how we "know" something. Before the advent of science, knowledge was obtained primarily by the following methods:

• Revelation
• Authority
• Moral insight
• Intuition
• Speculation
• Hopeful or wishful thinking
• Popular belief

Historically, these methods have almost always resulted in unreliable knowledge. This is especially evident in astronomy, physics, medicine, and society (e.g. race and gender). For example, the Catholic Church was the defining source of knowledge for hundreds of years. Its authority to determine knowledge was strictly enforced with coercion, threats, and death. For example, Galileo, who famously proposed that the earth moved around the sun instead of vice-versa, was imprisoned as a heretic by the Church. Galileo was in some sense lucky - Giordano Bruno, another philosopher who shared Galileo's views, was convicted of heresy and burned at the stake in 1600. Upon his conviction he famously replied, "Perhaps you, my judges, pronounce this sentence against me with greater fear than I receive it."

The Appeal of Nonscientific Methods

Despite their repeated failures in obtaining reliable knowledge, nonscientific methods of obtaining knowledge continue to be prevalent in society. Their continued appeal can be explained by several reasons:
• Nonscientific methods are:
• More appealing emotionally.
• Easier to learn and practice than scientific methods.
• Therefore most common, even in today’s society.

• Humans are conditioned from birth to follow authority figures and not to question their pronouncements. Knowledge imparted by authority figures is often unquestioned.

• Such conditioning is done by parents and teachers using a wide variety of positive and negative reinforcement techniques. Most individuals reach adulthood in this conditioned form, and accept the beliefs passed down from these authority figures.

Critical Thinking and the Scientific Method

Critical thinking can be described as problem-solving skills that result in reliable knowledge. It is the scientific method applied to everyday life. This is because the process of critical thinking is similar to the well-known method of scientific investigation. The scientific method uses observable and measurable evidence combined with logical reasoning to determine knowledge:

1) Observe a situation
• E.g. I notice that in my garden, some tomatoes are bigger than others.
2) Identify a question
• E.g. Does the amount of sunlight a tomato plant receives affect the size of its tomatoes?
3) Formulate a hypothesis
• The hypothesis suggests a proposed answer for the question.
• The hypothesis must be measurable in some way.
• E.g. "The more sunlight a tomato plant receives, the larger its tomatoes will grow."
4) Test and evaluate the hypothesis
• Gather and analyze the data in an experiment.
• Accept or reject the hypothesis.
• If you reject the hypothesis, go back to Step 3 and modify the hypothesis.
5) Draw reliable conclusions
• Re-test your hypothesis to confirm it.
• Revise your hypothesis if necessary.
• Extrapolate hypothesis into a theory.
• E.g. "All vegetables will grow bigger if they receive more sunlight."

Conclusions made from scientific reasoning lead to more reliable knowledge than other methods.

Warning Signs of Poor Critical Thinking

Be skeptical! Skepticism means that you should only believe something when there is sufficient and reliable evidence to support the belief. A skeptic knows that the attainment of reliable and true knowledge is no easy task. Be skeptical of all knowledge claims based on the following sources: