I want to read and learn all I can, write thoughtfully and truthfully, live according to reason and ever more mature wisdom, and savor every wonderful little gift of life.
What is it that makes astronomy a science and astrology a pseudoscience (only pretending to be real science)? Why is abnormal psychology a science, but not paranormal investigation? Evolutionary biology, but not creation science? Neuroscience, but not phrenology?
True sciences follow the scientific method of formulating a testable, or falsifiable, hypothesis and conducting experiments that either confirm or deny the hypothesis (and then repeating the experiments to eliminate room for accident). The procedures and order of steps may vary slightly from one science to another, but at the core, all true sciences make testable, falsifiable observations about their subject. Usually these observations could be disproven if only one counter-example is found.
Pseudosciences, on the other hand, usually make claims that cannot be disproven, at least not without impossibly exhaustive research and endless elimination of options. Many times their claims cannot be measured or tested, either. Although they claim to be sciences, pseudosciences do not follow the scientific method.
An example of a falsifiable, genuinely scientific claim is “Every living human has a heart.” Only one living human without a heart would be needed to disprove this claim; in other words, there is one clear way for the statement to be disproven. This makes the statement falsifiable. It is also, of course, measurable and testable.
An example of a non-scientific, non-falsifiable claim is “Every living human has a guardian angel.” Obviously this claim is not measurable and testable, but more to the point, it is also not falsifiable; this claim cannot be disproven. Therefore, it is not scientific.
Pseudosciences may have value, but that is not my point. My point is distinguishing between real science and pseudoscience. The difference comes down to whether it consistently makes observations that can be disproven. If it does, then it’s science. If it does not, it’s only pretending to be science.