Blew and yellow particles mixt, while they exhibit an uniform green, their extension is not perceiv’d; but as soon as they exhibit distinct sensations of blew and yellow, then their extension is perceiv’d. Distinct perception of visible ideas not so perfect as of tangible—tangible ideas being many at once equally vivid. Hence heterogeneous extension. Object. Why a mist increases not the apparent magnitude of an object, in proportion to the faintness(233)? Mem. To enquire touching the squaring of the circle, &c. That wch seems smooth & round to the touch may to sight seem quite otherwise. Hence no _necessary_ connexion betwixt visible ideas and tangible ones. In geometry it is not prov’d that an inch is divisible _ad infinitum_. Geometry not conversant about our compleat determined ideas of figures, for these are not divisible _ad infinitum_. Particular circles may be squar’d, for the circumference being given a diameter may be found betwixt wch & the true there is not any perceivable difference. Therefore there is no difference—extension being a perception; & a perception not perceivd is contradiction, nonsense, nothing. In vain to alledge the difference may be seen by magnifying-glasses, for in yt case there is (’tis true) a difference perceiv’d, but not between the same ideas, but others much greater, entirely different therefrom(234). Any visible circle possibly perceivable of any man may be squar’d, by the common way, most accurately; or even perceivable by any other being, see he never so acute, i.e. never so small an arch of a circle; this being wt makes the distinction between acute & dull sight, and not the m.v., as men are perhaps apt to think. The same is true of any tangible circle. Therefore further enquiry of accuracy in squaring or other curves is perfectly needless, & time thrown away. Mem. To press wt last precedes more homely, & so think on’t again. A meer line or distance is not made up of points, does not exist, cannot be imagin’d, or have an idea framed thereof,—no more than meer colour without extension(235). Mem. A great difference between _considering_ length wthout breadth, & having an _idea_ of, or _imagining_, length without breadth(236). Malbranch out touching the crystallines diminishing, L. 1. c. 6. ’Tis possible (& perhaps not very improbable, that is, is sometimes so) we may have the greatest pictures from the least objects. Therefore no necessary connexion betwixt visible & tangible ideas. These ideas, viz. great relation to _sphæra visualis_, or to the m. v. (wch is all that I would have meant by having a greater picture) & faintness, might possibly have stood for or signify’d small tangible extensions. Certainly the greater relation to s. v. and m. v. does frequently, in that men view little objects near the eye. Malbranch out in asserting we cannot possibly know whether there are 2 men in the world that see a thing of the same bigness. V. L. 1. c. 6.