I agree with DWill that this is a good analogy. On the other hand, I am not exactly arguing for lack of agency in "mythologizing" the way things are done - only arguing that a lot of our abstract systems are "carts" to explain the "horse" of practical arrangements. The explanations can be quite impressive in their inventiveness.
I was doing some thinking about changes of whole systems of explanation. Some are relatively easy to describe and even to invent because the purpose is fairly clear. So when the French Revolution wanted to substitute democracy and liberty for aristocracy, everyone understood what these were to do: to "rule" or "govern", i.e. to make laws and policy and put them into practice. But if we Progressive Christians want to substitute different idea structures for the traditional one, we run into the problem that it is not clear what the new order is supposed to be better at. The definitions of goals like "worshipping God" are themselves up for grabs.
This mattered a lot at the time of the Protestant Reformation. Calvin was a lawyer and saw himself reforming the system of making rules for people's lives, and so we get the Calvinist strict rules about the Sabbath, about plain clothing (among the Roundheads who overthrew Charles I, for example - they were Calvinists) and even about such things as dancing. The Puritans were Calvinists.
Luther was more of a theologian, and wanted people's understanding of salvation to change to rid Christianity of materialist abuses such as the sale of indulgences. Thus Lutherans went down a rather different road with structures (there are Lutheran bishops, for example, but no Reformed bishops).
What interests me the most about this is that they had to have a theory for what was supposed to be happening in order to revise how it was to be done. In both cases they wanted an alternative to the church hierarchy, and the Bible had to serve as the alternate authority. Then the implications were developed over time, in dialogue with each other and with moderates like Erasmus of Rotterdam.
Out of the blue today it occurred to me to wonder how different the U.S. would have been if Lincoln had not been assassinated. He wanted to bind up the wounds - would he have allowed the Democrats of the South to reenter more easily and thus, perhaps, not interfered as much in their society as the Radical Republicans did? Might he even have accepted local decision on citizenship and voting rights, rather than passing the 14th Amendment? If the white Southern rebels had re-entered easily, they could have blocked some of those reforms we treasure, and the South would have been even more oppressive than the Jim Crow system that evolved after the 1876 election travesty and the Plessy v. Ferguson case. It's an odd thought, that John Wilkes Booth may have been responsible for the 14th Amendment.
It was a revolutionary moment (or perhaps one should say "liminal"), when the system was changing drastically. Black people in the North were certainly free of being kidnapped as supposed "property", but their status was anything but settled. And so people had to debate what was the "right" way to organize things, with the previous way having been discredited but, again, the goal itself up for debate.
It's conceptually much simpler to say we are going to change the types of cars we drive, to cut out internal combustion, or even to change voting to ranked preference to eliminate the tyranny of extremism, than to figure out, as the Supreme Court is now trying to do, what is the purpose of protection of free speech. Is anything involving any political expression protected from compulsion, as the recent decision on public sector unions implies? Since there is no consensus on what freedom of speech is meant to achieve, the question of what political view it protects has become the determining factor in legal reasoning about whether particular types of expression are protected, which is a disturbing trend. (Of course conservatives might argue that things were already decided that way, as the decision in Citizen's United implies.)
I think such cases of open-ended goals being revised might explain some of the bizarre conflation of fact-claims with political opinions these days. Since an argument for the other "side" of an issue carries implications about which values should be attended to, fact claims become part of a dispute that is larger than the dispute about the facts themselves. As much as we might wish that the fact issues would be separated out and addressed independently, in politics this was never treated with the respect it deserved. McCarthy was repudiated not because he was lying, but because he started lying about the Army, an institution seen as fundamental to security (and not plausibly Communist).
Yes, I think this might be worth thinking about along these lines. The paranoid imaginings about what the other side is "up to" are more likely, and more likely to catch on, when the point of our institutional arrangement is still not settled or well understood.
Liberals are plausibly trying to "re-think" the Second Amendment, to at least help in drawing clear balancing tests of its priority against other competing priorities. But this opens the door to conservatives imagining what conclusions might be arising in liberal minds, some of the imagined results being realistic and others not. It's a "theory of mind" about the other, when we are called on not just to imagine chess moves from the perspective of the other, but the whole set of mental connections and how they arise.
Well, trying to sift this down to a conclusion, I'm not sure unclear purposes are a hornet's nest when we are re-thinking our abstract systems, but they do seem to be a complication. Arranging new institutions without a clear consensus on what the purposes should be, of either the old or the new institution, is almost guaranteed to be very "cart-like" with an absence of "horse".
I always consider "explain the purpose" to be fundamental to good communication. (Giving reasons for orders may not be the only criterion for a good manager - but it is an important one, at least outside the military.) Ironically, the Constitution does explain the purpose of the Second Amendment - in fact it is virtually the only part of the Bill of Rights that supplies reasoning. Yet people are ignoring that anyway.