Chinese is an extremely ancient system of writing. What is even more amazing that it only went through relatively small amount of change through its 3500 years of evolution, which can be divided into 5 major stages:
• Jiaguwen, or Oracle Bone Script. This is the earliest form of Chinese writing, likely used from the Middle to the Late Shang dynasty (approximately 1500 BCE to 1000 BCE). This script was etched onto turtle shells and animals bones, which were then used for divination in the royal Shang court, hence the name "oracle bones". Consequently, scholars have been using oracle bones as historical documents to investigate the reigns of later Shang monarchs, and surprisingly confirming the veracity of the traditional list of Chinese emperors that was deemed mythological rather than historical. The shape of these characters are often described as "pictographic", in that they resemble stylized drawings of objects they represent.
• Dazhuan, or Greater Seal. This stage of Chinese writing flourished from the Late Shang to the Western Chou dynasties (1100 BCE to 700 BCE). Unlike Jiaguwen, which was carved on bones, Da zhuan mainly appeared on cast bronze vessels. In fact, Jiaguwen and Dazhuan overlapped in time, and they might have been the same script but as they were inscribed on different surface types their visual styles differ due to the quality of the surfaces.
• Xiaozhuan, or Lesser Seal. This elegant script is the direct parent of the modern, un-simplified Chinese script. Whereas Dazhuan characters still resemble Jiaguwen and hence somewhat "pictographic", Xiaozhuan characters are more linear, but have not attained the "angular" look of later Chinese scripts. This script has survived the passage of time and continues to be used in the present age in calligraphy and seals.
• Lishu, or Clerkly Script. As its name implies, this script was used by government bureaucrats. While it probably appeared at approximately 500 BCE, Lishu became widely used in the Qin (221 to 207 BCE) and Han (206 BCE to 220 CE) dyansties when the bureaucrats needed a fast and efficient script to handle state matters. The marked difference between this script and the Xiaozhuan is that Li Shu characters have less strokes and a more flowing style, therefore easily adaptable to brushes and pens. Lishu is still occassionally used in the modern age.
The shape of Lishu characters are identical to modern Chinese characters, Furthermore, characters were standardized to remove regional variations, and these standard characters are for the most part the same characters written in the present. Therefore, it can be said that Chinese writing reached its maturity at this time (until the 20th century).
Evolution of Chinese writing after Lishu is a trend of increasing cursive scripts. These scripts are the ones used in calligraphy.
• Kaishu, or Standard Script, is essentially the traditional script used today (except in the People's Republic of China). It is very similar to Lishu, but slightly more cursive and contains serif-like (hook or anchor-like) elements at the corners and end of strokes. Kaishu appeared toward the end of the Han dynasty (220 CE).
• Xingshu, or Running Script, can be considered a cursive version of Kaishu. Often several strokes are merged into one, especially sequential dots or two strokes perpendicular to each other. It also appeared shortly after the Han dynasty.
• Caoshu, or Grass Script, is the most cursive Chinese script. It appeared during the Qin dynasty. The shape of its characters often do not resemble the corresponding Lishu or Kaishu character, in that some strokes are merged into one and others are simply left out.
The most important change in Chinese writing since the standardization in the Qin dynasty occurred in the middle of the 20th century. In 1949, the People's Republic of China (PRC) introduced simplified characters (jiantizi) to replace the traditional Kaishu characters. In addition to PRC, Singapore also adopted this script. However, other Chinese-speaking places such as Taiwan, Hong Kong, and various Chinese communities in Southeast Asia and the Americas rejected this new system and continued to use the traditional script. Tradition runs deep in Chinese culture, and the fact that the simplified script carried politic issues, certainly did not help its wider acceptance.
Not all characters were given a new simplified form, as these unsimplified characters were already very "simple" and involve very few strokes. Some simplified characters were in fact official recognition of widely-used colloquial variants of traditional characters.
The following chart lists of some Chinese characters through time:
The Origin of Chinese Writing
The precursor to Chinese writing, though, is still poorly understood. In many pots, jades, and bronzes ranging from the late third millenium BC to as late as Shang and Chou dynasties, bird and sun motifs appear together, often joined, and possibly can be read as yang niao, or "sun birds", the name of a local eastern Yi group which had settled in the Lower Yangtze valley. This could be an example of the a precursor to Chinese writing.
Current theories and evidence pinpoints the first emergence of Chinese writing in the East Coasts between the Late Neolithic and the early Bronze (aka dynastic) times. The culture which occupied this area was characterized by a high degree of social organization, particularly in pottery production (parts of their pots were made separately and later assembled together). It could be that this "standardization" led to the necessity of recording dimension of pots as well as the number of pots produced, thus the impetus to create a systematic way of recording number and objects.
The Earliest Chinese Writing
Whatever the obscure initial phase of written Chinese was, its appearance during the Shang already gives sign of a very complex system. Phoneticism was widespread in the form of the rebus principle, which means many words with the same sound can be, and were, written with the same sign. A most common example in English is to use pictures of a bee and a leaf to write belief. This leads to ambiguity in written text (if you're a Chinese speaker, think of the confusion that would be generated if you write "horse head" and "harbor" the same).
To alleviate the ambiguity, scribes started to attached additional symbols to clarify the meaning. In modern Chinese studies these signs are called "radicals". Also, the phonetic "spelling" of words was standardized, in that while previously two signs represented the same sound, only one of them continued to be used while the other became obsolete.
Sometimes new signs were created by combining two signs and the meaning of these two signs. Thus, the sign for "bright" is a combination of signs for "sun" and "moon".
Because of changes in the language such as sound changes, the introduction of tones, and branching into new languages, the phonetic part of many modern characters no longer provide any clue on how to pronounce the characters. Therefore learning Chinese becomes a matter of memorizing forms with only an occasional help. It is because of this that the Chinese writing system is misleadingly labeled as "ideographic", because, as many would argue, every sign stands for an idea. This is untrue and pretty absurd, as a writing system records a language, not replicates ideas, emotions, or other mental states. In essence, Chinese is "logographic", that is, its symbols write out words.