Thomas Kuhn suggests that the problem that Darwin presented to the modern mind was not evolution as such. The idea that man had evolved from preceding forms of more and more primitive life had been present for some time in various modes. In all of these forms, however, there was always a goal, a telos, to the process. Whether an idea in the mind of God or a plan inherent in nature the process of evolution was being directed to a specific end. (171) The novelty of Darwin’s position was that evolution took place through the process of natural selection. That is, Darwin removed teleology from the equation. (172) One could say that Darwin moved evolution into pure immanence. While evolution was vastly accepted, Darwin deeply disturbed many with the idea that even the most intricate organisms and their parts, “were products of a process that moved from primitive beginnings but toward no goal.” (172) How is it possible to understand development and progress without a specific goal?
Kuhn sees Darwin’s transposition as analogous to the one that he proposes for our view of science. Kuhn questions the idea that there is “some one full, objective, true account of nature and that the proper understanding of scientific achievement is the extent it brings us closer to that goal.” (171) Thus, he states, “If we can learn to substitute evolution-from-what-we-do-know for evolution-toward-what-we-wish-to-know, a number of the vexing problems may vanish in the process.” (Ibid.) This is an outgrowth of Kuhn’s understanding of normal science as the solving of puzzles within a paradigm and as changes in paradigms as scientific revolutions at the end of which nature is constituted in a fundamentally different way. While the embracing of a new paradigm allows for the solving of previous anomalies, it presents new ones as well. Further, there is no way, for Kuhn, of establishing whether or not a new paradigm is closer to the reality of the natural world than the last. This is because scientists can only access nature through paradigms and there is no meta-paradigm capable of arbitrating between all the others. In short, science does not seem to be the cumulative process many believe it to be and even if it might be there seems to be no way to know this.
This presents intractable problems for the realist who believes that there is a natural world out there that science is getting closer and closer to discovering and understanding in its fullness. If there is no way of accessing this very natural world except through paradigms, which are contingent and non-cumulative, than how can one make the claim that science is touching on, let alone getting closer to, the real?
At this point one is likely tempted to call Kuhn a relativist. Many seemingly have. If there is no way of accessing nature except through, for example, Einstein’s or Newton’s theories than how can one tell which of the two is closer to it? Further, what type of truth does science offer and in what way can one say it has progressed? Kuhn’s response is that science does indeed progress. He states that, “Later scientific theories are better than earlier ones for solving puzzles in the often quite different environments to which they are applied.” (206, italics mine) It is in this way that science progresses. Yet, one may ask, again, in what way does this count as progress? If knowledge is justified-true-belief Kuhn seems to be asserting that science cannot be knowledgeable since it has no way of justifying its beliefs as true except through a particular and contingent paradigm which in part determines the very world it is trying to access. (Ibid.) Kuhn appears to be admitting as much when he argues that the notion of truth as a fit between reality and a theory’s ontology seems “illusive in principle” and implausible. (Ibid.) Kuhn should admit the epistemological contingency his theory leaves us in, i.e. admit he is a relativist. There are worse things one could be.