7. But to represent this more clearly; there are two ways whereby purity of heart serves to the acquirement of knowledge; by natural efficacy, and by the divine blessing. And first, by natural efficacy, either by clearing the medium, or by assisting the faculty. As to the former, we are assured, not only that the soul now sees through a medium, and that this medium is the body, but likewise that the grossness of this medium hinders the sight of the soul. Whence it follows, that whatever helps this medium, helps the sight of the soul. And this purity does; especially that eminent part of it which consists in chastity and temperance. For first, it composes the passions, especially that of lust, by that the animal spirits, and by that the blood. For the motion of the passions ferments the spirits, and the fermentation of the spirits agitates the blood, and by that agitation raises all the feculent and drossy parts of it, and makes it like a troubled fountain, thick and muddy. And therefore it is, that men in any passion can’t reason so clearly, as when they are in more quiet and silence of spirit. But by purity all this disturbance is allayed, the passions are becalmed, the spirits fixed, the fountain of the blood cleared up, and so all the inner part of the glass, through which we see, becomes more bright and transparent, more apt to transmit the rays of light to the soul, which consequently sees more clearly through it.
8. But this is not all: for purity clears the outward part of the glass too. First by consequence, because the finer the spirits and blood are, the finer will be the threads of the outward veil also. Then more directly; because temperance refines and subtilizes the texture of the body, and diminishes its bulk and grossness, and unloads the soul of a good part of that burthen, which not only presses down her aspirations, but also hinders her sight.
*9. And as purity thus clears the medium, so it also assists the faculty. And that by the same general way, by composing the passions, which otherwise not only trouble and thicken the medium, but also divide and disperse the faculty. For the more things a man desires, the more he will be engaged to think on; and the more he thinks on at once, the more languid and confused will his conceptions be. But purity, by composing the passions, contracts the desires, and by contracting these, it contracts also the thoughts; whereby a man is reduced to a greater unity, simplicity and recollection of mind; and having but few thoughts to divide him, is the better able to think clearly.
10. Purity of heart serves to the acquirement of knowledge, secondly, by the divine blessing. It invites not only the Holy Spirit, but also the Father and the Son, even the whole Godhead, to come and dwell in the soul. This we are assured of from our Lord’s own mouth: _He that loveth me, shall be loved of my Father, and I will love him and manifest myself to him_. And again, _If a man love me, my Father will love him, and we will come unto him, and make our abode with him_. The chaste and good soul shall not only be loved by God, but be also of his council and privacy. This is the beloved disciple, who has the privilege to lean upon the bosom of his Lord, and to be admitted to his most secret communications. And therefore says the psalmist, _The secret of the Lord is with them that fear him_. And of _Ananias_, _Azarias_, and _Misael_, who refused to defile themselves with the king’s meat, it is said, _That God gave them knowledge and skill in all learning and wisdom_.
11. The third and last way of consulting God is by prayer. This also is a method which the scripture advises us to. _If any of you lack wisdom, let him ask of God, who giveth to every man liberally, and upbraideth not, and it shall be given him._ And this we know was the method whereby the wisest of men obtained his unparalleled wisdom. For as wisdom was his choice, so the method of his seeking and gaining it was by prayer.