We all know the value of a good dictionary. For a child or a young adult making their way in a world of antiquated literature and the diseased mutterings of the overly erudite, a dictionary is a good friend, a fine companion and an essential aide in gaining the vocabulary of adulthood.

Where it fails is in any other usage. Now, don't get me wrong - a good dictionary can probably stop a small bullet in a pinch, or be used for starting a fire.

But when you're looking to define your position in an argument a dictionary is a liability.

You see, dictionaries aren't written by the spectral god of the English language, or put together by a magical team of accuracy pixies in a mystical fairyland of unconvincingly rhythmic hammers and toys. Their terms are written according to a couple of criteria - they need to be apt, they need to be brief, and they don't need to be in-depth. That's the job of an encyclopaedia. 

Dictionaries tend to be written and edited by rather dull people with great loves for overpriced cheeses, tweed, and Proust - the kinds of people you'd probably never listen to about anything interesting, if only because they're unlikely to raise an interesting subject.

And yet vast swathes of people worldwide rely on them as if these people are not only worth listening to, but the only people worth listening to. it's frankly bizarre. You know what you mean; why do you need someone else to say it for you?

One of the clearest signs that someone doesn't know what they are talking about is when they reach for the dictionary when attempting to define the terms of a debate. If you need to post the definition of, say, 'conservative' or 'Christian' or 'donkey' in your article or response, you only show that you don't understand the term.

Why?

Well, I'm glad you asked. You see, all language is fundamentally subjective. We each understand words differently, particularly complicated words or ones loaded with meaning. Love, for example. We all agree to some degree about its meaning, but the intensity and associated feelings differ.  Mercy is another - who is it for? What does it involve? These are questions we each answer ourselves in defining the word. it's not that everyone has their own dialect, merely that interpretation is deeply personal. 

The clearest way of seeing this is in reading two translations of the same piece of foreign language material by different translators. The gist will be the same. But the nuances reflect the different weightings and values of the translators. The value and meaning of a word is entirely contingent on the author.

It's no different in politics, sport, or any other part of life. If the best way of expressing your opinion is to quote the Oxford, maybe you need to think about the topic a little more. Because if you can't trust yourself to use the right words properly and make your own (correct) decisions about what a word means, why should others trust you to make the right decisions on your subject matter?

So next time you're tempted to reach for a dictionary to define a word you already know, ask yourself why you're doing it. If it's because you want to be right, perhaps you shouldn't be writing that article/response yet. Until you can understand what you mean, you'll never convince someone else and you'll give your readers a poor impression of you.