The point of studying logic (call it critical thinking if the term logic makes you shudder) is to discover more about a situation than might be obvious—to understand not only what’s being said, but what’s being implied as well. A student of mine this past week was troubled by a sentence he read in a logic exercise, and his questions can help us understand how grammar and thinking go hand in hand.
The sentence he struggled with is from Arthur Conan Doyle’s novel The Hound of the Baskervilles (Doyle was the author of the many famous Sherlock Holmes detective stories). As you read it, try to identify the complete subject (all the words that name what the sentence is about) and its one verb. The sentence has no fewer than four verbs (one is a verb phrase), but you’re looking for the one that says something directly about the complete subject. Here’s the sentence: The western window through which he had stared so intently has, I noticed, one peculiarity above all other windows in the house—it commands the nearest outlook on to the moor.
The study of logic teaches how to discover what is necessarily implied in what someone has asserted. We put our thoughts into words, and those words together take on a meaningful shape which, if we can understand it exactly, will reveal what is folded into the words but not made explicit (interestingly, the root of the verb imply means just that, to fold or wrap together). So if we examine Doyle’s sentence closely, we will have to conclude that the complete subject, what he ultimately wants to say something about, comprises these ten words: the western window through which he had stared so intently. The standard declarative word order in English is a subject followed by its verb, and so we might be tempted here to conclude too quickly that western window is the subject and had stared is its verb. That, though, would be to overlook the relative clause, a major element in English sentence structure, and just what is at issue here as we try to find out what this sentence is implying. The verb for the complete subject, then, is not had stared, but the one simple word has.
A relative clause is a group of words with its own subject and verb, and it begins, with one exception we will look at presently, with the relative pronoun. The three major relative pronouns are who, which, and that, and so in Doyle’s sentence, we can confidently say that which he had stared so intently makes up the relative clause (with he the subject, and had stared its verb). In fact, though, we have left out one word, the preposition through, and this demonstrates the one exception to the rule that a relative clause always begins with its relative pronoun: except when the relative pronoun (here which) is the object of a preposition. So, in fact, our relative clause is through which he had stared so intently.
Now that is important to see because relative clauses more often than not act as adjectives for the noun they have followed. The noun before the relative clause here is window, which has already been qualified by another adjective, western. Because there is no comma between the noun window and the relative clause that follows it, we must conclude that the relative clause is giving information that defines, not merely describes, the window—in much the same way we understand the function of the adjective western. Both these adjectives, western and through which he had stared so intently, are therefore called restrictive elements, because they restrict, or limit, the window we are to think about as the sentence unfolds.
So what does all this mean about what’s being logically implied in the sentence? If I ask someone to hand me that black pencil, it’s very likely (though not unwaveringly certain) I’m using the adjective black to distinguish the pencil I want from others on the table. Likewise, when Doyle qualifies the western window with the restrictive relative clause through which he had stared so intently, he is strongly implying that there were other western-facing windows, none of which, though, had the peculiarity of commanding the nearest view of the moor: only the one through which he had stared did. To have added a comma after window would have made the same relative clause nonrestrictive, simply saying something more about the window, but not identifying a defining (and eventually consequential) attribute of it.
This window, though, the western one through which he had stared so intently, had an angle of view or some other distinguishing characteristic that made some further knowledge possible for the character who looked through it, a piece of information material, no doubt, to the puzzle of the case. We are led to picture, then, one wall of windows facing west perhaps, or a house of many windows across many walls and rooms looking west. That’s quite an interesting house or manor for us to imagine. All of which is to say that words in sentences conjure worlds, and if those worlds are meant to be rational worlds, then the sentences a writer assembles will give us logical information—sometimes explicit, sometimes not—in their very structure. The result for us as readers will be to see more deeply into a richer world, filled perhaps at times with implications we might not have suspected.