instances. A lens originally meant a lenticular shaped or double convex piece of glass, that being the kind of glass most frequently used by opticians. But as glasses of other shapes came to be used along with lenses, the name was extended to concave or even to perfectly flat pieces of glass. The words lever, plane, cone, cylinder, arc, conic section, curve, prism, magnet, pendulum, ray, light, and many others, have been similarly generalized.

In common language we may observe that even proper or singular names are often generalized, as when in the time of Cicero a good actor was called a Roscius after an actor of preeminent talent. The name Cæsar was adopted by the successor of Julius Cæsar as an official name of the Emperor, with which it gradually became synonymous, so that in the present day the Kaisers of Austria and the Czars of Russia both take their title from Cæsar. Even the abstract name Cæsarism has been formed to express a kind of imperial system as established by Cæsar. The celebrated tower built by a king of Egypt on the island of Pharos, at the entrance of the harbour of Alexandria, has caused lighthouses to be called phares in French, and pharos in obsolete English. From the celebrated Roman General Quintus Fabius Maximus any one who avoids bringing a contest to a crisis is said to pursue a Fabian policy.

In science also singular names are often extended, as when the fixed stars are called distant suns, or the companions of Jupiter are called his moons. It is indeed one theory, and a probable one, that all general names were created by the process of generalization going on in the early ages of human progress. As the comprehension of general notions requires higher intellect than the apprehension of singular and concrete things, it seems natural that names should at first denote individual objects, and should afterwards be extended to classes, We have a

glimpse of this process in the case of the Australian natives who had been accustomed to call a large dog Cadli, but when horses were first introduced into the country they adopted this name as the nearest description of a horse. A very similar incident is related by Captain Cook of the natives of Otaheite. It may be objected, however, that a certain process of judgment must have been exerted before the suitability of a name to a particular thing could have been perceived, and it may be considered probable that specialization as well as generalization must have acted in the earliest origin of language much as it does at present.

Specialization is an exactly opposite process to generalization and is almost equally important. It consists in narrowing the extension of meaning of a general name, so that it comes to be the name only of an individual or a minor part of the original class. It is thus we are furnished with the requisite names for a multitude of new implements, occupations and ideas with which we deal in advancing civilization. The name physician is derived from the Greek pvoikós, natural, and puris, nature, so that it properly means one who has studied nature, especially the nature of the human body. It has become restricted, however, to those who use this knowledge for medical purposes, and the investigators of natural science have been obliged to adopt the new name physicist. The name naturalist has been similarly restricted to those who study animated nature. The name surgeon originally meant handicraftsman, being a corruption of chirurgeon, derived from the Greek yeɩpoupyós, hand-worker. It has long been specialized however to those who perform the mechanical parts of the sanatory art.

Language abounds with equally good examples. Minister originally meant a servant, or one who acted as a minor of another. Now it often means specially the most

important man in the kingdom. A chancellor was a clerk or even a door-keeper who sat in a place separated by bars or cancelli in the offices of the Roman Emperor's palace; now it is always the name of a high or even the highest dignitary. Peer was an equal (Latin, Par), and we still speak of being tried by our peers; but now, by the strange accidents of language, it means the few who are superior to the rest of the Queen's subjects in rank. Deacon, Bishop, Clerk, Queen, Captain, General, are all words which have undergone a like process of specialization. In such words as telegraph, rail, signal, station, and many words relating to new inventions, we may trace the progress of change in a lifetime.

One effect of this process of specialization is very soon to create a difference between any two words which happen from some reason to be synonymous. Two or more words are said to be synonymous (from the Greek σúv, with, and ovopa, name) when they have the same meaning, as in the case, perhaps, of teacher and instructor, similarity and resemblance, beginning and commencement, sameness and identity, hypothesis and supposition, intension and comprehension. But the fact is that words commonly called synonymous are seldom perfectly so, and there are almost always shades of difference in meaning or use, which are explained in such works as Crabb's English Synonyms. A process called by Coleridge desynonymization, and by Herbert Spencer differentiation, is always going on, which tends to specialize one of a pair of synonymous words to one meaning and the other to another. Thus wave and billow originally meant exactly the same physical effect, but poets have now appropriated the word 'billow,' whereas wave is used chiefly in practical and scientific matters. Undulation is a third synonym, which will probably become the sole scientific term for a wave in course of time. Cab was originally a mere

abbreviation of cabriolet, and therefore of similar meaning, but it is now specialized to mean almost exclusively a hackney cab. In America car is becoming restricted to the meaning of a railway car.

It may be remarked that it is a logical defect in a language to possess a great number of synonymous terms, since we acquire the habit of using them indifferently without being sure that they are not subject to ambiguities and obscure differences of meaning. The English language is especially subject to the inconvenience of having a complete series of words derived from Greek or Latin roots nearly synonymous with other words of Saxon or French origin. The same statement may, in fact, be put into Saxon or classical English; and we often, as Whately has well remarked, seem to prove a statement by merely reproducing it in altered language. The rhetorical power of the language may be increased by the copiousness and variety of diction, but pitfalls are thus prepared for all kinds of fallacies. (See Lessons XX and XXI.)

In addition to the effects of generalization and specialization, vast additions and changes are made in language by the process of analogous or metaphorical extension of the meaning of words. This change may be said, no doubt, to consist in generalization, since there must always be a resemblance between the new and old applications of the term. But the resemblance is often one of a most distant and obscure kind, such as we should call analogy rather than identity. All words used metaphorically, or as similitudes, are cases of this process of extension. The name metaphor is derived from the Greek words μerá, over, and pepew, to carry; and expresses apparently the transference of a word from its ordinary to a peculiar purpose. Thus the old similitude of a ruler to the pilot of the vessel gives rise to many metaphors, as

in speaking of the Prime Minister being at the Helm of the State. The word governor, and all its derivatives, is, in fact, one result of this metaphor, being merely a corrupt form of gubernator, steersman. The words compass, polestar, ensign, anchor, and many others connected with navigation, are constantly used in a metaphorical manner. From the use of horses and hunting we derive another set of metaphors; as, in taking the reins of government, overturning the government, taking the bit between the teeth, the Government Whip, being heavily weighted, &c. No doubt it might be shewn that every other important occupation of life has furnished its corresponding stock of metaphors.

It is easy to shew, however, that this process, besides going on consciously at the present day, must have acted throughout the history of language, and that we owe to it almost all, or probably all, the words expressive of refined mental or spiritual ideas. The very word spirit, now the most refined and immaterial of ideas, is but the Latin spiritus, a gentle breeze or breathing; and inspiration, esprit, or wit, and many other words, are due to this metaphor. It is truly curious, however, that almost all the words in different languages denoting mind or soul imply the same analogy to breath. Thus, soul is from the Gothic root denoting a strong wind or storm; the Latin words animus and anima are supposed to be connected with the Greek ἄνεμος, wind; ψυχή is certainly derived from xw, to blow; πvevμa, air or breath, is used in the New Testament for Spiritual Being; and our word ghost has been asserted to have a similar origin.

Almost all the terms employed in mental philosophy or metaphysics, to denote actions or phenomena of mind, are ultimately derived from metaphors. Apprehension is the putting forward of the hand to take anything; comprehension is the taking of things together in a handful;