# Evolutionary Epistemology Popper has called his theory that knowledge can grow only by conjecture and refutation, as shown in [Science is Problem Solving](Science%20is%20Problem%20Solving.md), an **evolutionary epistemology**. While a [Problem](Problem.md) is still in the process of being solved we are dealing with a large, heterogeneous set of ideas, theories, and criteria, with many variants of each, all competing for survival. There is a continual turnover of theories as they are altered or replaced by new ones. So all the theories are being subjected to **variation** and **selection**, according to **criteria** which are themselves subject to variation and selection. The whole process resembles biological evolution. A [Problem](Problem.md) is like an ecological niche, and a theory is like a gene or a species which is being tested for viability in that niche. Variants of theories, like genetic mutations, are continually being created, and less successful variants become extinct when more successful variants take over. ‘Success’ is the ability to survive repeatedly under the selective pressures — criticism — brought to bear in that niche, and the criteria for that criticism depend partly on the physical characteristics of the niche and partly on the attributes of other genes and species (i.e. other ideas) that are already present there. The new world-view that may be implicit in a theory that solves a problem, and the distinctive features of a new species that takes over a niche, are emergent properties of the problem or niche. In other words, obtaining solutions is inherently complex. There is no simple way of discovering the true nature of planets, given (say) a critique of the celestial- sphere theory and some additional observations, just as there is no simple way of designing the DNA of a koala bear, given the properties of eucalyptus trees. Evolution, or trial and error — especially the focused, purposeful form of trial and error called scientific discovery — are the only ways. ## Scientific Discovery vs Biological Evolution We should not overstate the similarities between scientific discovery and biological evolution, for there are important differences too. One difference is that in biology variations (mutations) are random, blind and purposeless, while in human problem-solving the creation of new conjectures is itself a complex, knowledge-laden process driven by the intentions of the people concerned. Perhaps an even more important difference is that there is no biological equivalent of *argument*. All conjectures have to be tested experimentally, which is one reason why biological evolution is slower and less efficient by an astronomically large factor. This is what prompted popper to say "We can let our theories die in our place." --- Date: 20241018 Links to: [Fabric of Reality](Fabric%20of%20Reality.md) pg 68 Tags: References: * []()