§ 237. Preparatory to the consideration of the degrees of comparison, it is necessary to make some remarks upon a certain class of words, which, with considerable differences of signification, all agree in one fact, viz., all terminate in -er, or _t-er_. 1. Certain pronouns, as _ei-th-er_, _n-ei-th-er_, _whe-th-er_, or _o-th-er_. 2. Certain prepositions and adverbs, as _ov-er_, _und-er_, _af-t-er_. 3. Certain adjectives, with the form of the comparative, but the power of the positive degree; as _upp-er_, _und-er_, _inn-er_, _out-er_, _hind-er_. 4. All adjectives of the comparative degree; as _wis-er_, _strong-er_, _bett-er_, &c. Now what is the idea common to all these words, expressed by the sign -er, and connecting the four divisions into one class? It is not the mere idea of comparison; although it is the comparative degree, to the expression of which the affix in question is more particularly applied. Bopp, who has best generalised the view of these forms, considers the fundamental idea to be that of _duality_. In the comparative degree we have a relation between one object and _some_ other object like it, or a relation between two single elements of comparison: _A is wiser than B_. In the superlative degree we have a relation between one object and _all_ others like it, or a relation between one single and one complex element of comparison: _A is wiser than B, C, D_, &c. "As in comparatives a relation between _two_, and in superlatives a relation between _many_, lies at the bottom, it is natural that their suffixes should be transferred to other words, whose chief notion is individualised through that of duality or plurality."--"Vergleichende Grammatik," § 292, Eastwick's and Wilson's Translation. The most important proofs of the view adduced by Bopp are,-- 1. The Sanskrit form _kataras_ = _which of _two_ persons?_ is a comparative form; whilst _katamas_ = _which of more than two persons?_ a superlative form. Similarly, _êkataras_ = _one of two persons_; _êkatamas_ = _one of more than two persons_. 2. The Greek forms, ἑκάτερος = _each_ (_or either_) _out of two persons_; whilst ἕκαστος = _each or any out of more than two persons_. § 238. The more important of the specific modifications of the general idea involved in the comparison of two objects are,-- 1. Contrariety: as in _inner_, _outer_, _under_, _upper_, _over_. In Latin the words for _right_ and _left_ end in -er,--_dexter_, _sinister_. 2. Choice in the way of an alternative; as _either_, _neither_, _whether_, _other_.