While we start with a given set of characters making up Sun Tzu's The Art of War, there is still a serious question about what each of those character means, or rather, what each character meant in Sun Tzu's era.
As would be expected over long periods of time, there has been semantic drift. This means that the meaning of a specific character naturally changes over time as spoken words do. It is only when we take into account those current meanings that we can understand Sun Tzu's own re-definition of his concepts.
Of course, it is very easy for a translator to ignore these changes. This was true of the early, public domain translations of Sun Tzu, but it is just as true of many recent ones. It is simply too easy to go to the current meanings of characters. Too many translators use the modern meanings of the characters, which depart in many ways from the concepts Sun Tzu meant when he wrote.
Common Shifts of Meaning
This drift over thousands of years is serious because one of the more common changes is the reversal of meaning. We can see this drift in our own era, as in the slang meaning "bad" coming closer to the meaning of "good."
We should, however, point out that the meaning of the Chinese written language is more stable than that of Western languages. Written English from just eight hundred years ago is unintelligible to modern readers (read Chaucer). This may be because of the separation between the written language and the spoken one. Modern dictionaries are not a useful guide in translating Sun Tzu.
However, because of the use of modern dictionaries in translating Sun Tzu, many people think they are following Sun Tzu's advice when in fact they are doing just the opposite of what he taught. Many of the ancient Chinese characters have actually reversed their meaning over time. For example, one character that once meant "order" now means "chaos." Other characters actually mean both one thing and their opposite. For example, the ideogram for "stay" also means "leave," depending on the context. The idea of "complementary opposites" plays a key role, not only in Sun Tzu's The Art of War, but in all of Chinese science and philosophy. If you read all the popular translations, you discover that some of these reversals can create contradictory advice. Sun Tzu says one thing according to one translator and the opposite according to another translator.
The Context of the Period
The meaning of any set of Chinese characters comes largely from the context of the period. However, though he wrote about the same time as Lao Tzu developed the Tao Te Ching, Sun Tzu uses many key Chinese characters very differently. For example, he defined the key concept of tao very differently than did Lao Tzu. Lao Tzu considered the tao the spiritual essence of natural systems, while Sun Tzu used the term to mean the shared mission, goals, and values that hold an organization together. In many ways, Sun Tzu used his work to develop a specific vocabulary for the study of competitive organizations and strategic situations.
To get a Sun Tzu's meaning, it is certainly helpful to review the other classics of the period, most specifically the Tao. However, translators also have to be wary of their own philosophical prejudices. A Taoist is more likely to translate Sun Tzu from a Toaist point of view. It is helpful to know that there has never been an agreement in Chinese about Sun Tzu's philosophy. Of course, Westerners come to the text with their own philosophical baggage as well.
What most people are unwilling or unable to do is to look at the major philosophies of that period as opposed to our own as the proper starting point for defining Sun Tzu.
The Change in Writing Methods
Even the way characters were written was different in Sun Tzu's era from modern Chinese. The earliest Chinese is found carved into bones and is known as oracle bone script. In Sun Tzu's era, Chinese was written as detailed pictographs with a metal stylus on bamboo. This is known as the seal script. During Sun Tzu's period, the fifth century BC, different areas of China even used different character forms in seal script. The seal script pictograms were much less abstract than latter brush writing forms.
The First Emperor of Qin, who unified China in 221 BC, introduced the Qin brush script as the official writing, and from there on all the unified states had to use it in their affairs. The calligraphic brush style of this early period is the "clerical script," or lishu, which is easily readable today, even to the uninitiated. However, the pictograp. Its characters are still recognizable today. See examples above.
No copies of the original seal script of Sun Tzu text exists, a few fragments may have been found in the oldest archeological digs. What is usually found and what has been passed down through history are written in various later forms of brush script.
Today we rely upon Chinese researchers who compile Sun Tzu's work to choose the appropriate characters. It should be noted, however, that these are different than the reformed character set used in mainland China. You can see a sample of the Chinese text (as written today) with a transliteration and English sentence translation here.
Of course, the best method is to use Sun Tzu's definitions for characters, which he provides in detail in his work, rather than relying on dictionary definitions. Unfortunately, his definitions are usually too detailed and complex, making them unworkable in simple translation.