This diagram is known as the Tai Chi Tu, which is used in Daoist philosophy to conceptualise the flow of energy in the world. The black is referred to as Yin, which represents associations like "dark", "cold", "female", "negative" and "latent". The white is referred to as Yang, which represents associations like "light", "warmth", "male", "positive" and "active". It is a common mistake of westerners to make the jump and assume that Yin is evil and Yang is good. This kind of thinking should be avoided. It is very important in Daoist philosophy that there is no ultimate truth in concepts like "good" or "evil": while it is acknowledged that concepts such as good and evil do exist, they are social constructs that have been invented by society to regulate the behaviour of its "unenlightened" members.
Because Daoists do not believe that good and evil exist as universal truths, they do not believe in notions of "heaven" or "hell", in which an external, supreme being punishes the evil for their misbehaviour and blesses the good according to their benevolence. Some would call this a recipe for anarchy: If there is no punishment for evil deeds, it might be easier to do bad; if there is no one to reward good behaviour, the motivation for being good might not be quite so strong. Yet, the model Daoist lives in such harmony with his surroundings that we must re-examine what's at play here.
The ideas of Yin and Yang can help to clarify. The Tai Chi Tu itself has a kind "dynamic" quality: it looks as though the black and white sections of the diagram are in motion. This is because Yin and Yang are conceived of as transitory forms of energy. They are thought of as continuously changing into one another. As soon as energy is transformed into Yin, it no sooner becomes Yang and so forth. This speaks to us of the fleeting nature of life and the world: no sooner has something that we find pleasurable occurred before we are subjected to some sort of suffering. Westerners tend to want to avoid suffering. We see it as some kind of punishment (fair or unfair) that a cunning or rich individual can try (and maybe succeed) to avoid. We live for the "good times", indulging ourselves in them as something we deserve and resenting moments or periods of suffering.
Daoism, through concepts of Yin and Yang, will teach us that neither the periods of abundance nor the periods of suffering can be avoided, thus it is pointless to resist either. Moreover, it teaches that a person cannot know happiness until he has known sadness, cannot know abundance until he has known lack - even the extent to which we are able to realise our abundance or want depends on the extent to which we have experienced its counterpart: someone who has known only a little sadness is not able to recognise happiness that is any more extreme than the sadness he has expreienced. Thus Daoists do not couple up resentment with suffering and euforia with thriving in the sense that these two states are opposites. Instead, they see the one as necessarily leading into the other in a neverending cycle. They do not grieve in suffering any more than they rejoice in thriving. Just like Yin cannot exist without Yang, states of suffering and thriving cannot exist without each other. Daoists attempt to endure the times of suffering, knowing that because of the suffering they will have a keener sense for the times of thriving; they attempt to experience the times of plenty without forgetting that the reason they are sensitive to what is "good" is only because they have experienced what is "bad", also remembering that these times of plenty will not last forever, yet will come again.
Finally, (and I know I haven't done this wonderfully complex philosophy any justice), let's consider the little dots of Yin in Yang and Yang in Yin. This represents that neither can exist without the other, as I've explained above. It also conveys that there is always something of the one in the other: always some dark in the light, some light in the dark, some suffering in times of plenty and some rejoicing that's to be done in times of suffering.
We've not even come to the Daoist concept of WuWei, "action without action", which is a major philosophical building block of this way of living, but perhaps this is a topic for another discussion. For now, I can refer anyone who's interested in learning more to the Dao De Jing, which is the book of wisdom for Daoists, written by the famous mythical figure Laozi (pronounced "La-u-tze"). Having studied the original texts in class for a little while, I find it difficult to link you to an internet translation that says it in the way that has been so profoundly meaningful to me. I would advise anyone with enough time to go to an original Chinese version and to use a dictionary to look up all the original meanings of the characters. That way, you might arrive at a translation or understanding that is particularly meaningful to you.
The first line of the Dao De Jing in Chinese is pronounced "Dao ke dao fei chang dao". Literally, "dao" = path, way of thought, manner, even a literal path you follow; "ke" = can; "dao" = to think, to follow, to behave a certain way; "fei" = not; "chang" = original, true. Thus, my own translation to myself is "Any way of thinking or being which can be fully comprehended or followed is not the highest form/ true nature of thinking or being. To me, it acknowledges the utter mystery and complexity of God (=Dao), without directly contradicting itself by then attempting to offer a solution or explanation!
I hope this has been helpful, but if there's anything more that anyone's wondering about, don't hesitate to comment!
