But that this may be made more _Plain_, I must first examine the _difference_ between _Imagination_, and _pure Intellection_, or _Understanding_. So, for example, when I _Imagine_ a Triangle, I do not only _Understand_ that it is a _figure comprehended_ by _three Lines_, but I also _behold_ with the _eye_ of my _mind_ those _three lines_ as it were _before Me_, and this is that which I call _imagination_. But if I convert my Thoughts to a _Chiliogone_, or _Figure consisting_ of a _Thousand Angles_, I know as well that this Is a _figure comprehended_ by a _Thousand sides_, as I know that a _Triangle_ is a _Figure Consisting_ of _three sides_; but I do not in the same Manner _Imagine_, or _behold_ as _present_ those _thousand sides_, as I do the _three sides_ of a _Triangle_. And tho at the time when I so think of a _Chiliogone_, I may _confusedly_ represent to my self some _Figure_ (because whenever I Think of a _Corporeal Object_, I am used to _Imagine_ some _Shape_ or other) yet ’tis evident that this _Representation_ is not a _Chiliogone_, because ’tis in nothing _different_ from what I should Represent to my self if I thought of a _Milion-angled figure_, or any other Figure of _More sides_; Neither does such a _Confused Representation_ help me in the least to know those _Properties_, by which a _Chiliogone_ differs from other _Polygones_ or _Manyangled Figures_. But if a Question be put concerning a _Pentagone_, I know I may _Understand its Shape_, as I _Understand_ the _Shape_, of a _Chiliogone_, without the help of _Imagination_, but I can also _imagine_ it, by applying the _Eye_ of my _Mind_ to its _Five sides_, and to the _Area_ or _space_ contained by Them; And herein I manifestly perceive that there is required a _peculiar sort_ of _Operation_ in the _Mind_ to _imagine_ a Thing, which I require not to _Understand_ a Thing; which _New Operation_ of the _Mind_ plainly shews the _difference_ between _imagination_ and _pure Intellection_.