Are literary or philosophical references to bubbles universal? What's the earliest reference to Bubbles as Children's toys? As Bubbles typically require soap or detergent, and they may not have been commonplace in history, when did "large bubbles" start becoming something universally understood?

This question merges two linked ones: the philosophy question and the soap question.

Man is a bubble

Philosophical reference to bubbles can be traced back to Latin and Greek authors (Nassichuk, 2015, from whom I draw much of the paragraphs below). The oldest mention is by Roman author Marcus Terentius Varro (116–27 BC) who wrote in the introduction of his agricultural treaty Rerum rusticarum

Ut dicitur, si est homo bulla, eo magis senex

For if, as they say, man is a bubble, all the more so is an old man

The aging author explains to his friend that while his book is imperfect, he still has to write it because human condition is fragile, expressed by this simple metaphor "man is a bubble". Ut dicitur implies that this was already a known proverb, so Varro was not original here.

A later mention is found in Charon or The Inspectors by Greek poet Lucian (c. 125 - c. 180), a dialogue between Hermes and Charon about the vanity of human wishes.

Charon: Come now, I will give you a similitude for the life of man. Have you ever stood at the foot of a waterfall, and marked the bubbles rising to the surface and gathering into foam? Some are quite small, and break as soon as they are born. Others last longer; new ones come to join them, and they swell up to a great size: yet in the end they burst, as surely as the rest; it cannot be otherwise. There you have human life. All men are bubbles, great or small, inflated with the breath of life. Some are destined to last for a brief space, others perish in the very moment of birth: but all must inevitably burst.

Note here that the bubbles are not soap bubbles, but regular water bubbles.

A third notable example is in the Satyricon of Roman author Petronius (c. 27 – 66), where a character laments the death of a friend:

Heu ! utres inflati ambulamus , minoris quam muscæ sumus ; quæ tamen aliquam virtutem habent : nos , non pluris sumus quam bullæ.

Alas! what are we but blown bladders on two legs? We're not worth as much as flies; they are some use, but we're no better than bubbles.

Homo bulla est (Homo bulla for short) was a cornucopia of metaphors and comparisons: fragility of human condition, brievety of life, frivolity, lightness, humans being full of air, instant disappearance etc. This versatile concept continued to be popular in the Middle Ages. Benedictine monk Bernard de Cluny in his poem De contemptu mundi (12th century):

Hic caput exerit, emicat, interit, est quasi bulla ;

Bulla citacius, aura fugacius haud perit ulla.

[Man] raises his head, he shines, he dies: he is like a bubble;

No bubble bursts more quickly, no breeze is more more transient.

These notions became solidly installed in the European cultural landscape, and Human bulla had a rich progeny in literature and arts, as it was adopted by philosophers, poets, and painters from the Middle Ages onward. In late 15th century, Bolognese humanist Filippo Beroaldo compiled bubble references in Proverbiorum oratio. Erasmus used it too. The concept was not limited to dark considerations on human frailty and was much used for mockery. For instance, Renaissance poet Nicolas Bourbon wrote epigrams against a fellow poet that he nicknamed Bulla, whose writings and character he found empty and frivolous.

As we will see in the next part, the water bubbles eventually morphed into soap bubbles.

->But what about soap bubbles?