Do we have a universal and well agreed upon definition of Science? originally appeared on Quora, the place to gain and share knowledge, empowering people to learn from others and better understand the world. You can follow Quora on Twitter, Facebook, and Google Plus.

This is called the problem of demarcation – drawing the boundary between science and non-science. It’s much harder than it looks. Not everything done in a lab, or by accredited professors at prominent institutions, or with expensive equipment, or published in refereed literature, is scientific. Attempts to demarcate the border between scientific and non-scientific activity either potentially put cases on the wrong side, or leave the border permeable. That is, the easy definitions of science either leave things out that we all agree on as science or include things that we don’t consider to be science.

An example of the first is string theory, which may not make any testable predictions but only rearrange the way we structure the theory. Over the past few years there have even been huge controversies in physics as to whether string theory is true science, with some physicists calling it akin to astrology due to its lack of predictions. My favorite example of the latter – of something that looks like a science in most definitions but is not – is “umbrella-ology,” or the study of umbrellas. You collect elaborate statistics on their size, colors, shapes; you check and recheck your work; and so forth. You may study umbrellas with the same care you collect statistics on an animal population – which would be scientific – but umbrellas? I don’t think so.

The difference between science and non-science is sometimes mixed up with the difference between scientific claims that look wrong but turn out to be true, and scientific claims that look true but turn out to be false. The discoverer of high-temperature superconductors by Georg Bednorz turned out to be true despite Bednorz’s original doubts about it. The discovery of cold fusion, announced in March 1989, turned out to be false despite Pons and Fleischmann’s insistence that it was scientifically valid.

In my view, all scientific discovery explicitly or implicitly involves the achievement of a “recognition” that something is present in the world. You see a shape – let’s say something that looks like Donald Trump – and you recognize that it is a person rather than a cardboard cutout or a hallucination because you walk around it, see it from different angles, see it behave. You grasp what it is from different angles and you understand how these angles all fit together. In science, too, you see something like a planet or protein or new species of animal and you recognize it in the sense that you come to understand how it appears or behaves in different contexts. You may end up mistaken, or change your mind about what it is you are recognizing, but getting that “grip” on it is the scientific moment. How you get that recognition – what method you use – is less important than the recognition itself.

This question originally appeared on Quora. More questions on Quora:

* Philosophy: What books can I read to learn more about philosophy?

* Science: What different types of science denial are there?

* Education: What are the best strategies for educators or scientists to deal with science denialism?

Photo Credit: Maximusnd/Getty Images