Indeed if we search to the bottom I believe we shall find, that the Corruption of the Heart contributes _more_ to the Cloudiness of the Head, than the Clearness of our Light does to the regularity of our Affections, and ’tis oftner seen that our vitious Inclinations keep us Ignorant, than that our Knowlege makes us Good, For it must be confess’d that Purity is not _always_ the product of Knowlege; tho the Understanding be appointed by the Author of Nature to direct and Govern the Will, yet many times its head-strong and Rebellious Subject rushes on precipitately, without, its directions. When a Truth comes thwart our Passions, when it dares contradict our mistaken Pleasures and supposed Interests, let the Light shine never so clear we shut our Eyes against it, will not be convinc’d, not because there’s any want of Evidence, but because we’re _unwilling_ to Obey. This is the Rise of all that Infidelity that appears in the World; it is not the Head but the Heart that is the Seat of Atheism. No Man without a brow of Brass, and an Impudence as strong as his Arguments are weak, cou’d demur to the convincing Proofs of Christianity, had not he contracted such diseases in his Passions as make him believe ’tis his Interest to oppose _those_ that he may gratify _these_. Yet this is no Objection against what we have been proving, it rather confirms what was said concerning the mutual Relation between the Understanding and the Will, and shews how necessary it is to take care of both, if we wou’d improve and advance either. * * * * * [Sidenote: _Where we must begin._] The result of all then, and what gives a satisfactory Answer to the Question where we must begin is this; that some Clearness of Head, some lower degrees of Knowledge, so much at least as will put us on endeavouring after more, is necessary to th’obtaining Purity of Heart, for tho some Persons whom we vulgarly call Ignorant may be honest and Vertuous, yet they are not so in these particulars in which they are Ignorant, but their Integrity in Practising what they know, tho it be but little, causes us to overlook that wherein they Ignorantly transgress. But then any eminent degree of Knowlege, especially of Moral and Divine Knowlege, which is most excellent because most necessary and useful, can never be obtain’d without considerable degrees of Purity: And afterwards when we have procur’d a competent measure of both, they mutually assist each other; the more Pure we are the clearer will our Knowlege be, and the more we Know the more we shall Purify. Accordingly therefore we shall first apply our selves to the Understanding, endeavouring to inform and put it right, and in the next place address to the Will, when we have touch’d upon a few Preliminaries, and endeavour’d to remove some Obstructions that are prejudicial to both. CHAP. II.