There are other methods of discovering and learning knowledge about nature, but science is the only method that results in the acquisition of reliable knowledge.

Reliable knowledge is knowledge that has a high probability of being true because its veracity has been justified by a reliable method. Reliable knowledge is sometimes called justified true belief, to distinguish reliable knowledge from belief that is false and unjustified or even true but unjustified.

Some make a distinction between belief and knowledge. Some believe that people’s belief is their knowledge and that the important distinction to be made is whether one’s knowledge or beliefs are true, and if true, are justifiably true.

The scientific method attempts to minimize the influence of bias or prejudice in the experimenter when testing a hypothesis or theory and bring about a position where validity may be attributed to the idea being tested.

Other ways of knowing are not considered reliable because their discovered knowledge is not justified. Science is a method that allows a person to possess, with the highest degree of certainty possible, reliable knowledge (justified true belief) about nature. The method used to justify scientific knowledge (thus make it reliable) is referred to as the scientific method.

Every person has knowledge or beliefs, but not all of each person’s knowledge is reliably true and justified. In fact, most individuals believe in things that are untrue or unjustified or both: most people possess a lot of unreliable knowledge.

Science is not merely a collection of facts, concepts, and useful ideas about nature, or even the systematic investigation of nature, although both are common definitions of science. Science is a method of investigating nature which discovers reliable knowledge about it. Carl Sagan stated that science as a way of thinking much more than it is a body of knowledge.

The word science pertains to knowledge: knowledge ascertained by observation and experiment, criticlly tested, systematized and brought together under general principles. It derives from the Latin scientia; to know.