"It seems necessary that I should say something of the word _Quantus_, from which the word Quantity is derived. _Quantus_ is the correlate of _Tantus_. _Tantus_, _Quantus_, are relative terms, applicable to all the objects to which we apply the terms Great, Little."--"Of two lines, we call the one _tantus_, the other _quantus_. The occasions on which we do so, are when the one is as long as the other."--"When we say that one thing is _tantus_, _quantus_ another, or one so great, as the other is great; the first is referred to the last, the _tantus_ to the _quantus_. The first is distinguished and named by the last. The _Quantus_ is the standard."--"On what account, then, is it that we give to any thing the name _Quantus_? As a standard by which to name another thing, _Tantus_. The thing called _Quantus_ is the previously known thing, the ascertained amount, by which we can mark and define the other amount." "_Talis_, _Qualis_, are applied to objects in the same way, on one account, as _Tantus_, _Quantus_, on another; and the explanation we gave of _Tantus_, _Quantus_, may be applied, _mutatis mutandis_, to the pair of relatives which we have now named. _Tantus_, _Quantus_, are names applied to objects on account of dimension. _Talis_, _Qualis_, are names applied to objects on account of all other sensations. We apply _Tantus_, _Quantus_, to a pair of objects when they are equal; we apply _Talis_, _Qualis_, to a pair of objects when they are alike. One of the objects is then the standard. The object _Qualis_ is that to which the reference is made." Compare the same work, vol. i. ch. ix. p. 225:--"The word _Such_ is a relative term, and always connotes so much of the meaning of some other term. When we call a thing _such_, it is always understood that it is such _as_ some other thing. Corresponding with our words _such as_, the Latins had _Talis_, _Qualis_."]