Isaac Newton was probably the single most important scientist in the history of the world. He found laws of nature that not only advanced our understanding of the natural world, but which were demonstrably true to everyday people who could use the inventions explained or made possible thanks to Newton's work.
Darwin came after Newton and provided an equally important and true account of the natural world. But Darwin's revolution was radically different from Newton's. The rules governing natural selection cannot be expressed as mathematical laws. No matter how many conditions precedent one lays out, there is no way to "solve for x" and determine the "result" of evolution at time "t". Both theories are equally true, but the world views they suggest are incompatible. The physics minded look out at a deterministic world, where inanimate objects collide like billiard balls leading to fully predictable results. Those under the sway of biology see an open ecology, full of possible futures where free will and social organization produce unpredictable results that, nevertheless, can be understood in scientific terms.
In the 20th Century, the concept of evolution has proved remarkably adept at helping us understand not just the natural world, but also ourselves. Human culture and it's sup-parts all seem to change in ways usefully described as evolution. At the human level, the world is an open ecological system, scientifically understandable, but far from predictable.
But Newton came first in time and dominated the Enlightenment. His revolution inspired thousands of men to apply Newtonian mechanics to every corner of human knowledge. Ideas like "ideology" or "phrenology" came out of the explicit belief that human history could be understood and Newtonian mechanics.
These were all dead ends. The correct science of human behavior is not at all like physics. This is obvious in the case of phrenology. Now labeled a "pseudoscience", phrenology described laws connecting the shape of our skulls and the action of our brains. The thing is, phrenology is correct: our behavior is controlled by our brains, and the physical structure of different brain locations can play a major role. The failure comes in the attempt to generate mechanical laws that produce fully determined results. If the underlying structures had, in fact, produced tell tale bumps, phrenology would still have been doomed. Why? Because the relations between those bumps and our behavior would be open and ecological, not determined and mechanical.
But not every Enlightenment attempt to graft Newton onto human behavior has been rejected. For some reason, economics has continued on a relentlessly Newtonian path, where professors work out the mechanics of equilibrium. In politics as well, the notion of "ideology", a "system of ideas" hangs on, even as professors are forced to introduce obvious epicycles like the notion of "the symbolic conservative who is operationally liberal." Both ideas are as false as phrenology. Economics has a well known reality problem and mountains of social science data demonstrate that political behavior is not ideological.
What is the difference between phrenology, ideology, and economics? All three have been disproved by reality, but only phrenology is considered laughably stupid. Why?