The estimation of magnitude by means of concepts of number (or their signs in Algebra) is mathematical; but that in mere intuition (by the measurement of the eye) is aesthetical. Now we can come by definite concepts of _how great_ a thing is, [only][44] by numbers, of which the unit is the measure (at all events by series of numbers progressing to infinity); and so far all logical estimation of magnitude is mathematical. But since the magnitude of the measure must then be assumed known, and this again is only to be estimated mathematically by means of numbers,--the unit of which must be another [smaller] measure,--we can never have a first or fundamental measure, and therefore can never have a definite concept of a given magnitude. So the estimation of the magnitude of the fundamental measure must consist in this, that we can immediately apprehend it in intuition and use it by the Imagination for the presentation of concepts of number. That is, all estimation of the magnitude of the objects of nature is in the end aesthetical (_i.e._ subjectively and not objectively determined). Now for the mathematical estimation of magnitude there is, indeed, no maximum (for the power of numbers extends to infinity); but for its aesthetical estimation there is always a maximum, and of this I say that if it is judged as the absolute measure than which no greater is possible subjectively (for the judging subject), it brings with it the Idea of the sublime and produces that emotion which no mathematical estimation of its magnitude by means of numbers can bring about (except so far as the aesthetical fundamental measure remains vividly in the Imagination). For the former only presents relative magnitude by means of comparison with others of the same kind; but the latter presents magnitude absolutely, so far as the mind can grasp it in an intuition. In receiving a quantum into the Imagination by intuition, in order to be able to use it for a measure or as a unit for the estimation of magnitude by means of numbers, there are two operations of the Imagination involved: _apprehension_ (_apprehensio_) and _comprehension_ (_comprehensio aesthetica_). As to apprehension there is no difficulty, for it can go on _ad infinitum_; but comprehension becomes harder the further apprehension advances, and soon attains to its maximum, viz. the aesthetically greatest fundamental measure for the estimation of magnitude. For when apprehension has gone so far that the partial representations of sensuous intuition at first apprehended begin to vanish in the Imagination, whilst this ever proceeds to the apprehension of others, then it loses as much on the one side as it gains on the other; and in comprehension there is a maximum beyond which it cannot go.