The words “authoritative” and “authoritarian” sound awfully similar, because they both share a common root word. Yes, they both have something to do with authority, but their definitions are vastly different. Indeed, confusing one term for the other could have a dramatic (and possibly confusing) impact on the meaning that you are trying to convey in your writing or speech. So, what’s the difference?
Authoritative refers to the quality of being trustworthy, dependable or reliable. If a source is being described as authoritative, then you can rest assured that it is going to be true and accurate. In the context of referring to a body of text, as would be the case with a guide or tutorial, it would mean the work is the absolute best. An authoritative guide is the definitive guide.
Another example is The Authoritative Calvin and Hobbes, a large format “treasury” or collection of Calvin and Hobbes comic strips. The choice of title for this compilation gives the impression that if you read just one Calvin and Hobbes book, this should be the one. It is definitive. It gives you everything that you’d want out of a little boy and his pet tiger.
Authoritarian, on the other hand, has more to do with a manner of government or control. The most common context is that of an authoritarian regime wherein the leader (or other authority figure) demands strict and absolute obedience. Individual freedom is discouraged in favor of following authority without question.
In many ways, the notion of an authoritarian arrangement or relationship is identical to that of an absolute dictatorship. You’ll do as you’re told and that’s the end of that. This is profoundly different from describing the Grammar 101 series on Beyond the Rhetoric as the authoritative source of tips on grammar, spelling and word choice. Not that anyone has done that… yet. 🙂