1. When all the leading terms relating to the same general subject are collected together, duly arranged, and appropriately defined, the definitions taken collectively constitute a brief treatise on that particular subject, and lend to each other a mutual interest which would be lost if the same definitions were disjoined by the artificial arrangement of an alphabetical vocabulary.
2. The association of words, according to their affinities of meaning, or according to their common relation to the same central idea, assists the memory, so that a collection of kindred words, with their definitions, will be more easily remembered than the same number of words and definitions that have no bond of mutual connection. Let, for instance, the various English terms that relate to the idea of Light be collected, arranged, and defined, the student will thereby be enabled to treasure up, in the space of an hour or two, a stock of information which would have required years to accumulate by consulting a dictionary, as the terms might occur from time to time in the course of his reading. Other subjects, as those of Color, Sound, Form, Number, Time, etc., might be mastered with a like facility; and in the course of a few months the learner might, in this manner, gain some knowledge of a large proportion of the more useful terms of the language.
3. A topical classification of words necessarily brings synonyms, or words of similar meaning, in juxtaposition. Now, it is much easier to learn to discriminate between words separated only by slight shades of difference in their meaning when they are defined and studied in connection with each other, than when they are considered separately.
4. The topical classification of words brings together the different terms derived from the same root. Now, the definition of a Latin or Greek root will frequently shed such a light upon a number of English terms derived from this root, as to render it unnecessary to define the derivatives separately, and thus an important saving of time and labor to the student is effected. The association of the derivatives with their root also aids the memory in retaining the entire family; for any one of the derivatives will suggest the idea of the root, and the recollection of the root will suggest all the derivatives with their significations. Another advantage of studying words in connection with their roots is, that this connection often gives a force and beauty to the meaning of the derivatives, which would be entirely lost in any definition that disregarded this connection.
Nearly all the Latin and Greek roots from which important English words have been derived will be found in the present work, the most of them occurring more than once. The study of this volume may therefore serve, in some degree, as a substitute for the study of the Latin and Greek languages.
The author would claim the following as points of special merit in his work, as compared with most other works analogous in their nature to the present:
1. The connection between the meaning of roots and that of their derivatives, has, in most instances, been clearly exhibited.
2. The connection between the primary and the secondary meanings of the same word has generally been traced, and the process by which one meaning has grown out of another has been pointed out.
3. The faulty method of defining by synonyms has been avoided, each definition being given in the form of a single short sentence, descriptive of the meaning of the word defined.
