24. Reason did indeed devise all these things, but it was not right reason. It was man, but not the wise man, that discovered them; just as they invented ships, in which we cross rivers and seas – ships fitted with sails for the purpose of catching the force of the winds, ships with rudders added at the stern in order to turn the vessel's course in one direction or another. The model followed was the fish, which steers itself by its tail, and by its slightest motion on this side or on that bends its swift course. 25. "But," says Posidonius, "the wise man did indeed discover all these things; they were, however, too petty for him to deal with himself and so he entrusted them to his meaner assistants." Not so; these early inventions were thought out by no other class of men than those who have them in charge to-day. We know that certain devices have come to light only within our own memory – such as the use of windows which admit the clear light through transparent tiles, and such as the vaulted baths, with pipes let into their walls for the purpose of diffusing the heat which maintains an even temperature in their lowest as well as in their highest spaces. Why need I mention the marble with which our temples and our private houses are resplendent? Or the rounded and polished masses of stone by means of which we erect colonnades and buildings roomy enough for nations? Or our signs for whole words, which enable us to take down a speech, however rapidly uttered, matching speed of tongue by speed of hand? All this sort of thing has been devised by the lowest grade of slaves. 26. Wisdom's seat is higher; she trains not the hands, but is mistress of our minds.(Emphasis added - this is a reference to the invention and first use of glass windows.)
Any learned person of the time would have understood that different cultures have different levels of technology, and even that their own culture had simpler technologies in the distant past. Here, Seneca takes that understanding to the next level, that technological change has happened recently. He's so close but doesn't quite get there to realizing that technological change will keep happening. It would have been interesting to see what he or others might have anticipated, two thousand years ago.
He doesn't get there AFAICT because he's not interested in technology but rather in the nature of true wisdom, and in concluding that wisdom does not concern itself with practicalities.
Too bad - if Seneca and others like him had been more concerned with practicalities, maybe Roman technological improvements could've moved faster than they did.