A preface of mice and men
Take feces from a fat man and a thin, insert the "fat-shit" and "thin-shit" into the guts of mice. Feed all the mice the exact same diet, and those with "fat-man-shit" become fat, the rest thin.
This empiric result devastates the obviously true caloric theory of weight gain. Conclusion? Nature is under no obligation to make sense, at least not in complex domains. What is complexity? Abundance of moving parts. Think about the body, let us say it contains a billion species of bacteria, a thousand known nutrients, a thousand undiscovered nutrients and feedback mechanisms running in all directions. A certain bacterium might go berserk, consuming energy which otherwise would become fat, if it gets enough salt, another species of bacteria might speed down your metabolism if it gets enough vitamin D. Shit is rich in bacteria, so a shit-transplantation can cause drastic change to your metabolism.
The caloric-theory obviously is true: Calories in - calories out = Caloric increase = Weight increase. The problem with the theory is that both "calories in" and "calories out" are so complex that the simplicity of the theory becomes misleading enough to in practice be false. A grand, general theory is reduced to an imperfect heuristic.
Why start a review of Bastiat with a discussion of shit transplants? Because just as biology economics is complex. Hence obviously true ideas can be false. If we are lucky they can be used as imperfect heuristics.
Bastiat
Bastiat was a libertarian, at a time and in a country where big-business and the public were protectionists.
The main stream reasoned thus: England has an unfair advantage in the manufacture of textiles. They got into the game of industry early, and out-compete our good french tailors, the English take our jobs. We are reduced to importing clothes, which means that our wealth, our money, flows out of France leaving us poor. To solve all these problems we should protect French industry, by high tariffs on English goods."
Bastiat's counterpoint: Oh, you underestimate the gravity of our situation. There is a more dangerous foe. One that wreaks havoc on the candle industry, by an unfair fluke of nature this enemy can produce both light and heat more cheaply than us. Whom do I speak of? The sun!
This is Bastiat's typical style. He is humorous, and likes to show the flaws in the logic of his opponents by generalizing it in absurdum.
His economic ideas were not new. It is all a rehash of Adam Smith: Belief in free trade and the advantages of specialization. The value of Bastiat rather lies in that he was a great author, his examples help you to absorb ideas you already that you just were familiar with.
So: reading him helps you internalize a bunch of obviously true ideas. But in economics as in biology the obviously true, sometimes is false in practice.
The half-learned, or those with incentives to misunderstand, tend to leach on to the clear logic of authors like Bastiat, and to then out of hand dismiss opposing beliefs. Scroll through the reviews of this book, and you will find dozens of five-star-reviews claiming that everyone who is not Libertarian is an idiot, or that if everyone just followed the ideas from this book everything would be great.
Even if theories cannot fully explain the complex, useful heuristics are possible. Knowledge of the kind "people who eat herring tend to be healthy" or "those with power tend to get corrupt" or "industrialists tend to want protectionism for their business" - is possible.
Empirically Bastiat's heuristics are quite good, even if he personally might have believed that they were laws.
Some interesting passages and ideas in Bastiat
* A reflection that the benefits of protectionism are obvious, while those of free markets are hidden. We might illustrate (and expand on) the idea by a modern example.
Isn't it a tragedy that San Fransisco is so far behind Los Angeles in the movie business? If SF just used the same kind of barriers France has (mandating that x% of movies shown in theaters be French, subsidies, et cetera) then they would get a movie industry in no time at all. Protectionism would reliably cause a movie industry in SF. But there would be hidden downsides. For every person employed in the movie-business rents for offices and apartments would raise in SF. The increased costs would make the difference between survival and bankruptcy for a random sample of tech-entrepreneurs and businesses. But nobody would be able to prove that X-company failed because of the movie industry. Meanwhile LA would get slightly worse at making movies for each competent person who moved to SF. What would the effect be for a neutral party, like say Iceland? Worse movies and worse technology. The benefits are gathered and obvious, while the downsides are random and spread.