A clay tablet from over five thousand years ago, with a few signs pressed into it: a grain, a quantity, a personal name. You can identify them one by one, and still not read it as a sentence — there is no word order, nothing says who did what to whom. It is a receipt.
That is easy to file under "writing was still primitive". The interesting move is the opposite one: bookkeeping does not need sentences at all. For signs to be able to write any sentence, something apparently unrelated has to happen first — somebody has to take a drawn thing and use it to record the thing's sound.
The Sumerians did exactly that. After that step, what can be written down is no longer limited to what can be drawn: anything that can be said out loud can be written.
Start on this side of the threshold. The earliest writing generally accepted as such comes from Uruk in Mesopotamia, around 3300 BCE, and it is overwhelmingly accounting: a commodity, how much, to whom, the total. It usually cannot be read as a complete spoken sentence — word order, who did what, has no place on the tablet. Its own earlier ancestor was not even signs but small clay tokens sealed inside a ball, one token per sheep.
The step across the threshold is a sign switching from what it depicts to what it sounds like. Sumerian for "arrow" was ti, and "life" sounded close enough, so the sign that drew an arrow was borrowed to write "life". The trick is called the rebus principle. English plays the same game: draw an eye to mean the word I.
Chinese kept an unusually clean trace of this step. The oracle-bone form of 其 (qí) drew a winnowing basket — the tool for tossing grain — and that was its original meaning. But it was borrowed to write a near-homophonous pronoun, 其 (qí, "its"), so successfully that a new character 箕 (jī, "winnowing basket") eventually had to be made for the basket: the original owner was evicted from its own house.
Doing all this from scratch is currently credited only three or four times: Mesopotamia around 3300 BCE, Shang-dynasty oracle bones in China around 1200 BCE, and Mesoamerica around 500 BCE (the oldest surviving body is Zapotec stone carving). Whether Egypt around 3200 BCE counts as independent is argued over — it is close enough to Mesopotamia that what travelled may have been the idea that signs can record speech. On evidence strength: the dates and the independence claims are archaeological inference, and new finds move the numbers.
Every other script inherited the idea, and what gets inherited is usually not the shapes but the knowledge that this can be done. Japanese is the clear case: Chinese characters were first used purely for their sound values, a set called man'yōgana, then cursived and clipped — 安 (an) became the hiragana あ (a), and 伊 (i) lost a corner to become the katakana イ (i).
The deepest difference between scripts is not how they look but which layer of unit their signs point at. There are only three roads: point at a phoneme — the smallest sound unit that distinguishes meaning — and you have an alphabet; point at a syllable and you have a syllabary; point at a morpheme, the smallest meaningful unit, and you are on the road Chinese characters took.
Which road is passable is largely fixed by how many syllables the language has. Standard Japanese has only about 100 distinct syllables, so forty-odd basic signs in each of the two kana sets are enough. Most syllables in Cherokee, a North American Indigenous language, are open — a consonant plus a vowel — so 85 signs cover it too.
English cannot go this way. Estimates of how many syllables it permits differ wildly by method, from a few thousand to around thirty thousand; on any of them, one sign per syllable is hopeless, and words like strengths, eight sounds in a single syllable, are everywhere. So it keeps splitting downward to the phoneme layer: two dozen-odd letters cover the sound system of the whole language. Mandarin has fewer than 1,300 distinct syllables counting tone, so a syllabary is in fact passable; characters took the morpheme road instead, and its costs and payoffs were added up in the topic on what makes Chinese unusual.
No script is pure, though. Over 90% of Chinese characters are phono-semantic, with the sound-bearing component sitting there in plain sight; but pronunciation kept shifting for centuries while the components did not, so only around 40% of those components now cue the reading reliably. Conversely, English letters quietly record morphemes: cats and dogs both end in s, yet the first is hissed and the second buzzed like a z. The spelling records the plural morpheme, not the sound of the moment.
So asking whether a script is phonetic or meaning-based gets you nothing. Ask two other things: which layer its signs mostly point at, and how many units that layer has in that particular language.
In 1821 a Cherokee man named Sequoyah finished something very hard. He could not read English; he only knew that talk on paper was a real thing. Over more than a decade he picked the syllables of Cherokee apart one at a time and gave each a sign, settling on 85. The uptake was startlingly fast: within a few years a great many people could read and write, and in 1828 the Cherokee Phoenix was printed in parallel Cherokee and English columns.
But the syllabary records two things not at all: Cherokee has tone, and it distinguishes vowel length, and neither is marked on the page. The result is that the words for water and salt are written as the same string of signs — what separates them is exactly vowel length. Someone who speaks the language tells them apart from context at a glance; someone who does not, cannot. This is not a design flaw: Sequoyah built it for people who already spoke Cherokee, and a distinction a native speaker restores on his own need not take up space on the page.
Arabic and Hebrew push the same logic further: standard text does not write short vowels at all, a type of script called an abjad. It works because the meaning lives in the consonants. The three consonants k, t and b own the business of writing — kataba "he wrote", kitāb "book", kātib "writer", maktab "office" — and the vowels that come and go are carrying the grammar and the derivation. Drop them and the root is untouched. English cannot afford the move: strip the vowels from bit, bat, but and bet and all four become bt.
The other extreme records a distinction finer than the phoneme. In the Korean script Hangul, promulgated by King Sejong in 1443, the consonant letters are drawn after the place of articulation: ㄱ draws the back of the tongue rising to block the throat (the sound that starts go), ㄴ draws the tongue tip against the upper gum ridge (the sound that starts no), ㅁ is the square of the lips closing (the sound that starts me). That is a layer below the phoneme — where in the mouth the sound is made. And the alphabet road itself may have been opened only once: essentially every alphabetic script today traces back to the Proto-Sinaitic script, made by Semitic workers in Egypt around four thousand years ago out of borrowed hieroglyphic shapes, with Latin, Greek, Cyrillic, Hebrew and Arabic all on that line, and Hangul the acknowledged exception (the family tree is reconstructed from letter shapes and borrowing chains, and particular branches are still argued about).
So writing is not a mirror of language, it is a lossy record: it keeps only the distinctions its designer could hear and judged worth keeping, and leaves the rest for the reader to restore — which the reader manages because he already speaks the language. That is exactly where the topic on reading being an unprepared skill landed: speech grows by itself, literacy does not.
Sequoyah's choice shows you can generously drop a pile of distinctions when the users already speak the language; but the same economy badly disadvantages learners, including children of the community who never got the chance to speak it. The two needs genuinely conflict and there is no technically optimal answer, which is why the decision belongs to the speech community.
The missing step is quite specific: they have not gone to recording sound. As long as a sign only points at objects and feelings, what it can express is limited to what can be drawn. To become writing, somebody has to start using them to record pronunciation.
It means "guess the sound from the component" is a strategy that misleads you about half the time, and the child has no way to know in advance which half. It also explains why the entry period for this system is longer, while reading speed afterwards is not at a disadvantage.