Since the beginning of history, people have jumped to conclusions. Only afterward have they come up with reasons for those conclusions — all the while deluding themselves and others that the process happened in the other direction. This is what David Hume was talking about when he said “reason is, and ought only to be the slave of the passions.”
Slavery to the passions was a prime concern of all of the ancient Greek schools of philosophy. Even Aristippus, the founder of the hedonistic Cyrenaic school of philosophy, pointed out that there’s nothing wrong with going into a whorehouse — so long as one has the self-control to leave.
The ancient Greeks recognized that motivated reasoning makes you a slave to your passions, and that falling for the motivated reasoning of others can enslave you to their passions. They came up with a variety of ways for dealing with the problem.
The Pyrrhonist philosophers developed a conceptual framework for this problem, giving it a name that transliterates into English as dogmatism — a concept similar to but not identical with what we call “dogmatism” in English. They showed that dogmatic reasoning was not only egotistical (i.e., motivated reasoning), but that it that caused people to suffer unnecessarily.
The Sophists observed that there were at least two sides to every issue, and that good arguments could be created for each of those sides. They pioneered techniques to help people set aside one’s gut opinion of what was right so that the other sides could be rationally explored. Examples of this can be found in the Dissoi Logoi, a philosophical text that predates Socrates, and Gorgias’ masterpiece, Encomium for Helen, in which he finds a storehouse of reasons that Helen could not be held responsible for the Trojan War (belief in her guilt was nearly universal at the time).
The Academic Skeptics built on the work of the Sophists, requiring adherents to know and understand the arguments for the various perspectives on any issue under consideration. Only after going through this process was one to allow oneself to choose the side that seemed most plausible. Even then, the choice was to be considered provisional — and there was always the option of not choosing. Excellent examples…