"bedrock" vs. "hardpan" for "very basis; foundation"
What's the difference between those terms in regard to their figurative sense?
Can they be used just about interchangeably?
Consider the following examples:
Ownership of land is the bedrock of democracy.
Ownership of land is the hardpan of democracy.
-and-
Mutual trust is the bedrock of a relationship.
Mutual trust is the hardpan of a relationship.
bedrock Google Pictures:
noun
Geology. unbroken solid rock, overlaid in most places by soil or rock fragments.
bottom layer; lowest stratum.
any firm foundation or basis: Technical courses will be founded on a bedrock of sound, general education so as to produce a well-rounded engineer.
the fundamental principles, as of a teaching, belief, or science: Let's strip away the cant and get down to bedrock.
adjective
- basic; fundamental.
Etymology: 1840-50, Americanism; bed + rock
hardpan Google Pictures:
noun
Geology. any layer of firm detrital matter, as of clay, underlying soft soil.
hard, unbroken ground.
the fundamental or basic aspect of anything; solid foundation; underlying reality: the hardpan of mathematical theory.
Etymology: 1810-20, Americanism; hard + pan Random House
hard pan
The hard stratum of earth lying beneath the soil; hence, figuratively, the firm, substantial, fundamental part or quality of anything; as, the hard pan of character, of a matter in dispute, etc. Webster's 1913 Dictionary
The main difference between the two is that I hardly ever hear "hardpan" but "bedrock" is quite common. A Google search of "hardpan" yielded 400,000 results; of "bedrock, nearly 15 million. What's more, my spellcheck underlines "hardpan" as a word it doesn't recognize but not "bedrock." Whereas this doesn't address any disparity in meaning, it does touch on a significant gap that exists between the two words in being readily understood. A five-dollar word does you no good if everyone you use it on never has more than four fifty in their back pocket.
As for their meanings, I've always perceived a finespun difference between the two. "Bedrock" has always seemed more ostensible, like "cornerstone." It's openly known and utterly sublime to whatever one is figuratively building on it. "Hardpan" has always seemed more tenebrous, and obscure. It's underlying, but in a way that's more subliminal than sublime. That isn't to say that it's secret but just beneath the surface of reality's broad daylight. I don't know from where I ever drew that nuance, but I just asked my wife, and that's her take on it too, which leads me to believe there's something to it, even if it's subtle.
I've never heard "hardpan" used figuratively, and when it is used (with its literal meaning) it's often accompanied by some cusswords.
"Bedrock" is the established metaphor for "firm foundation" or "strong underlying principles". It generally has a positive connotation. "Hardpan", to those who even know what it means, is apt to have a negative connotation, as it's difficult to deal with in many situations -- hard to dig in, of unknown bearing capacity, etc.