Perhaps one of the most common questions I get asked as a witch (sometimes even by other witches) is whether I practise black magic or white magic. My answer is always the same: Neither. It's part of my practise to recognise the duality of nature; dark and light, male and female, negative and positive. Which means that I don't believe any kind of magic can be purely white or purely black.
First of all, let's look at how people generally define white magic and black magic. Any kind of magic performed with ill will i.e. the intention to cause harm to another, for destructive purposes or out of pure selfishness is generally seen as black magic. Conversely, magic performed with selfless intentions and a desire to do good, or else magic that is not intended to harm anybody, is seen as white magic.
But the fact is, magic is all about the manipulation of energy. No matter what we do, there are consequences; not always good and not always bad. It's impossible to control the way this butterfly effect works.
A good example of this is cruelty-free living. Even if you are a vegan who recycles everything and buys fair-trade and eco-friendly products, there'll always be a negative consequence of your lifestyle. Eating more fruit, vegetables and soya increases the demand for crop farms, which are often built through deforestation which ultimate puts wildlife at risk. This doesn't mean that you should give up your lifestyle or that it is ineffective, it just means that the universe requires a blend of different lifestyles to maintain this equilibrium.
A more literal example when it comes to magic is the use of nature in spells. What if a spell to draw love to you requires rose petals? You may go and pick a rose from your garden - harmless, right? Except that that rose provides food for bees which are essential for plant pollination and the survival of humanity.
I'm not trying to guilt trip anybody; but a healthy acknowledgement that all actions have consequences is the key to magical wisdom. It doesn't mean that we're to blame for bad things happening, so long as our intentions are sound, just that each and every one of us is a cog in a universal machine where the concepts of good and bad cannot exist without each other.
Within occult and ceremonial magic, black magic and white magic is sometimes known as the Left-Hand Path and Right-Hand Path - although many occult scholars disagree that these Paths refer to good or bad magic, rather, just different ways of practising. An altogether better way to talk about magical choices.
Aside from what has already been discussed, the idea of black magic and white magic is also problematic in that these days it has racist connotations. Black witches (i.e. witches who are black) often find themselves uncomfortable with that particular label because it is more suggestive of the type of magic they perform rather than of their race, and it also reflects poorly on types of magic within certain cultures such as the African-American Hoodoo practise or Haitian Vodou.
Black magic and white magic as concepts also make very good tools to open up modern witches to judgement, both from the Church and other magickal practitioners. Anyone can brand your idea of witchcraft as "black magic" whether you agree with that description or not, and not identifying as a "white witch" or showing any interest in "white magic" leads to accusations of dark deeds and even a disrespect for the code of Wicca. Apart from the fact that you don't have to be Wiccan to be a witch, there's nothing in Wiccan ethics that suggests you cannot perform magic for selfish reasons. It's "An it harm none do what ye will", not "Ye shall only use magic if it serves an altruistic purpose".
Next time someone quizzes you on your magical path, remember this quote from the holy 1996 cult film that is The Craft: "True magic is neither black nor white. It's both because nature is both. Loving and cruel, all at the same time. The only good or bad lies within the heart of the witch. Life keeps a balance all on its own."