in a particular order must have the same singularity of meaning as have two ordered symbols of a non-commutative algebra. Everyday discourse has functions other than those of mathematical symbolism, if only because it has to engage the interest of an audience. If the fact receives tardy recognition in elementary teaching of highly flexional languages, the study of completely isolating ones, e.g. of the Chinese group, or of an almost completely isolating language such as Anglo-American, forces us to recognize how extensively we rely on context to convey meaning without multiplication of verbal counters or of grammatical devices to complicate the rules of the game. Divorced from its context, we are free to interpret the couplet religious worker as: (a) any member of the working class with religious convictions or professions; (b) a person who does regular voluntary or paid work for a religious organization. In an actual slab of sustained discourse its organic relation to the semantic gestalt would rarely if ever give rise to misunderstanding between English-speaking people; and the disadvantages of sacrificing word-economy or economy of space and effort to legislate for so few occasions would outweigh the benefits.

To some extent, mathematics also relies on context to supply the necessary clue to correct interpretation. For instance, we interpret the cluster d²x both as a differential of the second order in the domain of the infinitesimal calculus and as the product of x and the square of d in the domain of elementary algebra. If we speak here or elsewhere of a couplet or compound as self-explicit, the epithet is therefore shorthand for sufficiently explicit in a context where it will commonly crop up. Context, and context alone, dictates how we interpret the vagaries of the allegedly "possessive" terminal 's in father's debts, father's death and father's dress-shirt. Context, and context alone, endorses the relationship implicit in churchyard, brickyard, backyard. A little reflection on such illustrations of its role should encourage the fastidious reader to take a tolerant view about the need for hard and fast rules for framing compounds whose meaning is sufficiently suggestive in an appropriate situation. Words are not mere atoms. They are organs of communication. As such, their functions inescapably depend on the whole body of discourse.

Reading and Self-expression

Three classes of difficulties discussed in what has gone before do not exhaust those which confront a person who is learning a language. Language-learning involves four skills as different as arithmetic, algebra, geometry and trigonometry.