… is from pages 4-5 of Liberty Fund’s 2017 expanded English-language edition, brilliantly edited by David Hart, of Frédéric Bastiat’s great work Economic Sophisms and “What Is Seen and What Is Not Seen”; specifically, it’s from Bastiat’s original (1846) “Author’s Introduction” to Sophisms (footnotes deleted; original emphasis):
Protection brings together in one single point all the good it does and distributes among the wider mass of people the harm it inflicts. One is visible to the naked eye, the other only to the mind’s eye. It is exactly the opposite for freedom.
This is so for almost all economic matters.
If you say: Here is a machine that has thrown thirty workers out into the street ;
Or else: Here is a spendthrift who will stimulate all forms of industry;
Or yet again: The conquest of Algiers has doubled Marseille’s trade;
Or lastly: The budget assures the livelihood of one hundred thousand families.
You will be understood by everyone, and your statements are clear, simple, and true in themselves. You may deduce the following principles from them:
Machines are harmful;
Luxury, conquest, and heavy taxes are a blessing;
And your theory will have all the more success in that you will be able to support it with irrefutable facts.
We, on the other hand, cannot stick to one cause and its immediate effect. We know that this effect itself becomes a cause in its turn. To judge a measure, it is therefore necessary for us to follow it through a sequence of results up to its final effect. And, since we must give utterance to the key word, we are reduced to reasoning.
But right away here we are, assailed by these cries, “You are theorists, metaphysicians, ideologues, utopians, and in thrall to rigid principles,” and all the prejudices of the public are turned against us.