Wisdom literature from very different times and places converges on a small number of practical recommendations. Most ancient advice hasn't survived; a handful has, across traditions with no contact.
What distinguishes the survivors is worth examining.
The recurring recommendations
Speak less. Appears in Greek, Hebrew, Chinese, Sanskrit and Arabic sources independently. The observations cluster around the same points: that speech is difficult to retract, that listening produces information while speaking produces none, and that the impulse to speak is strongest precisely when speaking is least advisable.
Moderate your appetites. Universal, and phrased in terms ranging from health to virtue to social consequence. The specific observation that satisfying a desire tends to increase rather than exhaust it appears repeatedly.
Consider the end. Reflection on mortality, on how things will look later, on the temporary nature of present circumstances. Present in essentially every tradition.
Delay your response to provocation. The specific advice to wait before reacting in anger appears with striking consistency, frequently with a recommended interval.
Choose your associates carefully. The claim that you become like the people around you, stated in various forms.
Attend to what is yours to control. Present in Stoic sources most explicitly and in others in different terms.
Reciprocity as a moral principle. Some version of treating others as you would be treated, appearing in a remarkable number of independent traditions.
What they have in common
Several features distinguish these from advice that didn't survive.
They address failure modes rather than prescribing goals. Each identifies a specific way people reliably go wrong, rather than describing what a good life looks like.
Goals are culturally variable. Failure modes appear to be more constant, which may be why the advice transfers.
They concern impulses that operate against long-term interest. Speaking, eating, reacting in anger, present-focused decision-making. In each case, an immediate pull towards something that produces later regret.
The modern vocabulary would describe these as failures of self-regulation, and the observation that they exist and cause problems doesn't require any particular framework.
They're negative rather than positive. Mostly instructions to refrain rather than to do. That's easier to apply, harder to get wrong, and less dependent on circumstance.
They're cheap to test. Anyone can check whether waiting before responding in anger produces better outcomes. Advice that can be verified in daily life has a transmission advantage over advice that can't.
What didn't survive
Instructive to note the categories that dropped away.
Specific practical instruction — how to farm, how to conduct business, how to treat illness — which was superseded by better information.
Advice tied to particular social arrangements, which stopped making sense when the arrangements changed.
Recommendations depending on cosmological claims that were abandoned.
And a great deal of advice that was simply wrong and was noticed to be wrong.
Which suggests a filter: what survived is what remained true when the world around it changed, which points at claims about human psychology rather than about circumstances.
The correspondence with modern findings
Several of these have modern analogues.
The advice to delay reactions corresponds to findings about emotion regulation and about the time course of anger.
Observations about appetite correspond to research on habituation and on the relationship between anticipation and satisfaction.
The recommendation about associates corresponds to research on social influence on behaviour.
Reflection on mortality corresponds to a literature on how salience of death affects priorities, though the findings there are more contested than popular accounts suggest.
The correspondence should be held loosely — retrofitting modern research onto ancient advice is easy and frequently misleading. What it does suggest is that the observations were about something real.
The limits
Worth stating.
Ancient wisdom literature also contains a great deal that we would now reject: assumptions about social hierarchy, about the status of women, about slavery, about outsiders.
Extracting the parts that survive means making selections, and the selection is being made by us according to our criteria. Which means the apparent convergence is partly a product of what we chose to notice.
That's a real caution against treating the survival of certain advice as evidence of its truth. It survived partly because we kept selecting it.
The practical upshot
The advice is genuinely useful and it's also unremarkable, which is the point.
Nobody needs an ancient source to be told to wait before responding in anger. The value of the ancient sources is not novelty but that they treat these as central rather than as obvious.
Which is the actual difficulty. Everyone knows this advice. Almost nobody applies it consistently, and the traditions that transmitted it understood that knowing and doing are different problems — which is why they attached practices rather than only stating principles.
The transmission mechanism
Worth asking how this material persisted, since most of what was written has not.
Several features helped. It was short and memorable, which suited oral transmission. It was attributed to named figures, which gave it authority. It was embedded in texts preserved for other reasons — scripture, epic, curriculum.
And it was useful enough to be repeated, which is the main filter. Advice that people found worth passing on survived; advice that was ignored did not, regardless of whether it was true.
That last point is a caution. The filter selects for memorability and apparent usefulness, which correlate imperfectly with accuracy. The survivors are the sayings people liked repeating, and liking is not the same as testing.