There is an interesting moment in the Platonic dialogue Protagoras where Socrates, the champion of seeking knowledge, also cautions us about the nature of knowledge.1 It occurs when a companion of Socrates calls on him in the early morning, eagerly entreating him to accompany him to listen to the great Sophist Protagoras. Socrates eventually agrees, but warns his over-eager companion. He reasons that Sophists are like any other merchant, but instead of physical goods, they deal in the “food of the soul.” To buy from them, therefore, is more risky since we tend to value our soul more than our body (or Socrates thinks we ought to). Socrates, thus, advises his companion to:

“Pause, and do not hazard your dearest interests at a game of change. For there is far greater peril in buying knowledge than in buying meal and drink…when you have paid for them you must receive them into the soul and go your way, either greatly harmed or greatly benefited; and therefore we should deliberate and take counsel with our elders [before buying knowledge]” (52-53).

There is the problem though–we could be “greatly benefited” by this new knowledge.2 But in order to judge for ourselves, we’ll have to expose ourselves to this new learning. Socrates is skeptical that we can judge for ourselves though, unless we already have a perfect understanding of good and evil, in which case we can safely buy knowledge of the Sophists (or anyone else for that matter).

Since Socrates is a firm believer that no one possesses that perfect understanding, it is hard to see that he gives us any choice but to try out new knowledge for ourselves. But he does at least advise us to proceed with caution, because new knowledge is not always a good thing. Learning something harmful to our souls is obviously bad. He suggests using our elders, who presumably have more wisdom, as sounding boards, and whom as a collective should have even more wisdom. This is the approach he takes in the dialogue, ensuring that others are there when he talks to Protagorus, because the more people are involved in the learning, the more chance they will have to spot error in this new knowledge Protagorus imparts. As he says later in the dialogue: “When two go together, one sees before the other, for all men who have a companion are readier in deed, word, or thought” (98).

Although this is merely the prologue to the dialogue with Protagorus, it resonates strongly with me. We have all heard the phrase “a little knowledge is a dangerous thing”, but knowledge itself can be dangerous to its acquirers. History is full of examples of ideologies that seemed so exciting at first but which ultimately proved catastrophic to human life. And yet, one cannot hide one’s head in the sand, and that is not what Socrates advises. He advises caution and deliberation.

It strikes me that how worried we should be about the harmful consequences of new knowledge depends entirely on our current state of wisdom. If our status quo is a state of extreme folly, it hardly matters whether the new knowledge will be good or bad. Even slightly bad new information might be better than whatever type of philosophy we are currently embracing. Likewise, if we are extremely wise, most new information will not be worth our time. Of course, Socrates himself would assert that all of us know next to nothing, and so we shouldn’t be afraid of the latter scenario. In which case, perhaps Socrates’ worry about the effects of bad “soul food” should concern us less.

I suspect that most of us, however, do not share the “Socratic wisdom” of assuming near-total ignorance. In which case, motivated reasoning is our friend here. Motivated reasoning is the tendency to favour new information when it conforms to pre-existing belief. And this appears to come standard with the ol’ basic human model; we’re pretty stubborn about changing our minds. But there are good reasons to be a motivated reasoner too; it’s not for nothing that this became a standard evolutionary adaptation. Taber and Lodge (2006) outline a variety of reasons which I discussed previously here. The most important two for our purposes here, however, are (1) because our priors have been developed through often careful thought or decades of experience and are thus pretty good, and (2) because it is smart to have a bit of natural suspicion and caution when encountering something novel. You want to be a little skeptical until you’re sure this new “soul food” tastes better than what you are currently consuming.

Of course, the brilliance of Plato’s writing is that he puts us in the exact same position as Socrates and his companion. Just as they try to decide whether it is worth putting their souls in jeopardy by hearing the new wisdom of the Sophists, we the reader encounter the same dilemma when encountering Platonic philosophy. Should we read it or not? And how will it affect us? I think it is nearly impossible not to be affected by Plato’s thought when reading it for the first time.3 It is why parables like the Cave still resonate so strongly with us millenia later. In Plato’s case, however, the risk of trying the “soul food” is undoubtedly worth it. I can hardly stand to watch movies from the 1980s, they seem so dated, and yet Plato’s work retains its savour after all these centuries.

  1. I will be using the translation found in Scott Buchanen’s The Portable Plato↩︎

  2. My sense is that the new knowledge Socrates refers to hear is more than just new mundane facts; “food of the soul” as knowledge must be ethical knowledge, or knowledge about what the good life consists of, or what virtue consists of. ↩︎

  3. I specify reading because many undergraduates would testify that listening to a professor drone on about Plato can make Plato’s thought leave a very light impression indeed. ↩︎