The American Pediatric Association is clear that spanking harms children both in the short and long runs. In the short run, it’s humiliating. In the long run, it can lead to mental health problems.

Its recommendations are based on evidence. It’s easy to spin yarns and weave anecdotes about how spanking builds character (“My parents spanked me and I turned out alright!”). But actual research implies (1) physical punishment is damaging to children’s mental health, even when it doesn’t harm the body, and (2) other forms of discipline improve behavior more effectively anyway (timeouts, consequences like putting away toys, etc.). So in light of information now available, it’s fair to say spanking children is immoral. (Despite that, it’s still common: recent data show that “24 percent of one-year-old children and 33 percent of 3-year-olds are spanked in a given month.”)

When I write spanking is immoral, I mean that about the present: those who spank in this day and age are doing wrong. But here’s a tricky question. How should our moral judgments of the present impact our judgments of what people did in the past?

Spanking is a case in point. Spanking used to be much more common, and it was even regarded as obligatory. The thought was that, if one didn’t spank, the child would fall into delinquency or have an ill-formed character. Hence the saying: “Spare the rod, spoil the child.” So if I morally condemn present spanking, should I extend my moral condemnation to past spanking too?

I can imagine three broad positions about morally judging the past in general.

1. Extreme Presentism: I should condemn past instances of any action that I would condemn in the present.
2. Temporal Relativism: I should not use present moral standards to condemn past actions at all, since the past was a different time with different moral standards in different places.
3. Moderate Presentism: It is sometimes fair to evaluate past actions in light of my present moral standards, but I should exercise caution, realize there are mitigating factors, and only condemn when there is a purpose in doing so.

I think it’s intuitive that Extreme Presentism and Temporal Relativism are misguided.

Temporal Relativism gives a pass to any actions that were commonly accepted. But consider this passage from Steven Pinker’s Better Angels of Our Nature, a book which chronicles declines in violence over the course of human history (see Pinker’s book for the sources of his quotations).

One survey found that in the second half of the 18th century, 100 percent of American children were beaten with a stick, whip, or other weapon. Children were also liable to punishment by the legal system. Until the 19th century, British law allowed the death penalty for “strong evidence of malice in a child seven to fourteen years of age,” and many teenagers continued to be hanged for petty crimes like arson and burglary until 1908, when the minimum age for execution was raised to sixteen. Even at the turn of the 20th century, German children “were regularly placed on a red-hot iron stove if obstinate, tied to their bed posts for days, thrown into cold water or snow to ‘harden’ them, [and] forced to kneel for hours every day against the wall on a log while parents ate and read.”

We would be remiss if we didn’t condemn the customs described in that passage. But that raises the question of what principle we should apply in condemning common customs from the past. Extreme Presentism furnishes an easy answer: we should apply present moral standards, whatever those happen to be.

Yet I don’t think we should accept Extreme Presentism either. First, it rules out the possibility that the past might have something to teach us morally. Second, Extreme Presentism foists on us the unnecessary burden of judging a lot of past actions, with little guide as to why we should be doing so. The past is full of billions of individual actions and thousands of customs and norms that would underwrite them. Having to condemn all the ones that don’t fit present morality would be practically impossible.

That leaves Moderate Presentism, which is plausible yet (so far) vague. But the current vagueness needn’t bother us, as long as we sharpen the position.

We could sharpen Moderate Presentism in several ways. One could, for example, list exonerating factors that excused past actions (e.g., false-yet-honestly-held descriptive beliefs that made certain actions seem beneficial even though they weren’t, where there was no reason people should have known better). But I want to focus on the final clause in the position, which is about the purpose of condemning the past. Why might we even bother?

In various ways, past customs are defaults for what we should do in the present. There are practical and symbolic dimensions to this.

Why, practically speaking, should we drive on the right side of the road in the United States? Even if there were no laws about this, there would be a simple answer: because that’s what we’ve done in the past. It’s hard to see how sophisticated human cooperation would be possible if there weren’t such practical defaults. In any complex cooperative activity, there are too many elements for all of them to be up for re-negotiation every time, so something has to provide defaults, and past customs and conventions are as good for that purpose as anything.

Symbolically, however, past customs also become ways of indicating one’s group identity. An American follows American customs. A Bulgarian follows Bulgarian customs. Etc. And it’s up to collective memory to say what those customs are (this is why people often falsify the past, mythologize it, or tell yarns). And a culture’s symbolic, identity-defining customs can be (from moral and/or practical standpoints) good, neutral, or bad. Presumably, coming together to share certain culinary delights is, all things considered, good as well as symbolic. Wearing certain colors on certain days is neutral, since it’s basically arbitrary and wouldn’t be good or bad either way apart from the symbolism.

But customs can also be bad yet held in place by the momentum that cultural symbols generally have. Spanking illustrates this. It is both immoral and without practical purpose (and is even instrumentally foolish, given what we know). But the person who says, “My parents spanked me and I turned out alright!” is really saying that belonging to that club is part of their identity, and they want their children to share whatever identity that is.

So for customs that have this symbolic aspect we should be especially vigilant in morally questioning the past—often using present moral standards to do so. One purpose of morally condemning the past is to rid ourselves of symbolic defaults, when they conflict with what we, from a non-symbolic standpoint, would regard as wrong. And that’s why the corporal punishment of children is worth condemning—also in the past.

In sum, I think we should be circumspect with regard to moral condemnation of the past, since Extreme Presentism is short sighted. But when past ill behaviors threaten to spill into the present as a part of misguided in-group symbolism, we should condemn them. Some symbols need to be shattered.