The nobel prize winning economist Joseph Stiglitz is very fond of quoting Thomas Jefferson. “Knowledge is like a candle; as it lights another candle, its original light is not diminished”.
Economists like Stiglitz refer to the opposite of this property as exclusivity. In other words if I eat a box of chocolates or turn a tree into timber, you can’t have the chocolates or enjoy the shade and scenic beauty provided by the tree. Only one of us can consume a consumable. On the other hand if I have an idea I can share it with you, if you are interested. If my idea happens to be a good one then denying access to it, or the right to use it, gives rise to an inefficiency. Traditional intellectual property is based on such exclusion. Knowledge is a global public good that is of potential benefit to anyone in the world. There is a global social cost in depriving anyone in the world the right to use available knowledge.
Most of our individual ideas are “memes”. In other words we have all been lit from someone else’s candle. Originality in science is extremely difficult and is only partially achieved even by the small handful of creative individuals that manage to provide a new spark. We all worry that we are wrong or being too derivative when we think or write about scientific issues but I have (quite recently) come to the conclusion that we really shouldn’t be worried that our ideas are not original providing we are casting some light, somewhere. The more candles that are out there, the more light is cast and the collective effect is to everyone’s benefit.
In the open source model of software development the light cast has an even more positive effect, because software is itself useful as a tool for achieving other goals. Software developers in fact make some of the candles. I have neither the time nor the ability to contribute code to open source projects, but I appreciate the tremendous generosity of all those who do and try to support and use open source alternatives to commercial software as a matter of principle.