The natural sciences are often seen to rely on evidence, rationality and the quest for deeper understanding. Observation and experimentation play a key role, and terms such as “theory” have a special meaning in the natural sciences compared to how they are used in daily life and in other areas of knowledge.
• The success of the natural sciences has led some people to see them as the most important form of knowledge.
• The main difference between science and pseudo-science is that scientific hypotheses can be tested, and pseudo-scientific ones cannot.
• According to the traditional picture of the scientific method, science consists of five key steps: observation, hypothesis, experiment, law, and theory.
• Among the problems that arise in applying the scientific method are that observation is selective and that you are more likely to notice things that confirm your hypothesis than those that contradict it.
• Since scientific laws are based on a limited number of observations, we can never be sure that they are true.
• According to Karl Popper, science should be based on the method
of conjectures and refutations, and scientists should try to falsify hypotheses rather than verify them.
• In practice, a hypothesis can no more be conclusively falsified than it can be conclusively verified.
• Thomas Kuhn drew attention to the role played by paradigms in science and argued that the history of science is punctuated by revolutionary jumps or 'paradigm shifts'.
• Although scientific beliefs change over time, it could be argued that each new theory is closer to the truth than the previous one.
• Despite the success of the natural sciences, they cannot give us absolute certainty, and there are many perplexing questions that lie beyond their scope.