become as it were popular) of the mastering spirit, of men unlucky and ill omened, of the glances of love, envy, and the like. With this is joined the inquiry how to raise and fortify the imagination; for if the imagination fortified have so much power, it is worth while to know how to fortify and exalt it. And here comes in crookedly and dangerously a palliation and defence of a great part of ceremonial magic. For it may be speciously pretended that ceremonies, characters, charms, gesticulations, amulets, and the like, do not derive their power from any tacit or sacramental contract with evil spirits, but serve only to strengthen and exalt the imagination of him who uses them. As likewise in religion the use of images to fix the cogitations and raise the devotions of those who pray before them has grown common. My own judgment however is this: though it be admitted, that imagination has power, and further that ceremonies fortify and strengthen that power; and that they be used sincerely and intentionally for that purpose, and as a physical remedy, without any the least thought of inviting thereby the aid of spirits; they are nevertheless to be held unlawful, as opposing and disputing that divine sentence passed upon man for sin, "In the sweat of thy face shalt thou eat bread." 1 For magic of this kind proposes to attain those noble fruits which God ordained to be bought at the price of labour by a few easy and slothful observances.

as

There remain two doctrines, which refer principally to the faculties of the inferior or sensible soul, that which is most connected with the organs of the body; the one concerning Voluntary Motion, the other

1 Gen. iii. 19.

concerning Sense and the Sensible.

In the first of

For

these, which has in other respects also been very barrenly inquired, one entire part almost is wanting. the proper office and structure of the nerves and muscles, and of the other parts required for this motion; and what part of the body is at rest, while another moves; and that the imagination is as it were the director and driver of this motion, insomuch that when the image which is the object of the motion is withdrawn the motion itself is immediately interrupted and stopped (as in walking, if you begin to think eagerly and fixedly of something else, you immediately stand still); these, I say, and some other subtleties which are not amiss, have long ago come into observation and inquiry. But how the compressions, dilatations, and agitations of the spirit (which is doubtless the source of motion) can sway, excite, or impel the corporeal and gross mass of the parts, has not as yet been diligently inquired and handled. And no wonder; seeing the sensible soul has been regarded rather as a function than as a substance. But since it is now known that it is itself a corporeal and material substance, it is necessary to inquire by what efforts a spirit so small and tender can put in motion bodies so gross and hard. Of this part therefore, since it is deficient, .et inquiry be made.

Concerning Sense and the Sensible there has been much fuller and more diligent inquiry, both in general treatises concerning them and also in particular arts, as perspective and music; how correctly, is nothing to the purpose, seeing they cannot be ranked as deficients. Yet there are two noble and distinguished parts, which I pronounce deficient in this doctrine; the one con

cerning the Difference of Perception and Sense, the other concerning the Form of Light.

A good explanation of the difference between Perception and Sense should have been prefixed by philosophers to their treatises on Sense and the Sensible, as a matter most fundamental. For we see that all natural bodies have a manifest power of perception, and also a kind of choice in receiving what is agreeable, and avoiding what is hostile and foreign. Nor am I speaking only of the more subtle perceptions, as when the magnet attracts iron, flame leaps towards naphtha, one bubble coming near another unites with it, rays of light start away from a white object, the body of an animal assimilates things that are useful and excerns things that are not so, part of a sponge attracts water (though held too high to touch it) and expels air, and the like. For what need is there of enumerating such things? since no body when placed near another either changes it or is changed by it, unless a reciprocal perception precede the operation. A body perceives the passages by which it enters; it perceives the force of another body to which it yields; it perceives the removal of another body which held it fast, when it recovers itself; it perceives the disruption of its continuity, which for a time it resists; in short there is Perception everywhere. And air perceives heat and cold so acutely, that its perception is far more subtle than that of the human touch, which yet is reputed the normal measure of heat and cold. It seems then that in regard to this doctrine men have committed two faults; one, that they have for the most part left it untouched and unhandled (though it be a most noble subject); the other, that they who have happened to

turn their minds to it have gone too far, and attributed sense to all bodies; so that it were a kind of impiety to pluck off the branch of a tree, lest it should groan, like Polydorus. But they should have examined the difference between perception and sense, not only in sensible as compared with insensible bodies (as plants with animals), one body with another; but also in the sensible body itself they should have observed what is the reason why so many actions are performed without any sense at all; why food is digested and ejected; humours and juices carried up and down; the heart and the pulse beat; the entrails, like so many workshops, perform every one its own work; and yet all these and many other things are done without sense. But men have not seen clearly enough of what nature the action of sense is; and what kind of body, what length of time, or what repetition of impression is required to produce pleasure or pain. In a word, they do not seem at all to understand the difference between simple perception and sense; nor how far perception may take place without sense. Neither is this a dispute about words merely, but about a matter of great importance. Concerning this doctrine then (being of great use and bearing upon very many things) let a better inquiry be set on foot. For ignorance on this point drove some of the ancient philosophers to suppose that a soul was infused into all bodies without distinction; for they could not conceive how there could be motion at dis cretion without sense, or sense without a soul.

That no due investigation has been made concerning the Form of Light (especially as men have taken great pains about perspective) may be considered an

1 Virg. Æn. iii. 39.

astonishing piece of negligence. For neither in perspective nor otherwise has any inquiry been made about Light which is of any value. The radiations of it are handled, not the origins. But it is the placing of perspective among the mathematics that has caused this defect, and others of the kind; for thus a premature departure has been made from Physics. Again the manner in which Light and its causes are handled. in Physics is somewhat superstitious, as if it were a thing half way between things divine and things natural; insomuch that some of the Platonists have made it older than matter itself; asserting upon a most vain notion that when space was spread forth it was filled first with light, and afterwards with body; whereas the Holy Scriptures distinctly state that there was a dark mass of heaven and earth before light was created. And where the subject is handled physically and according to sense, it comes at once to questions of radiation; so that there is but little physical inquiry extant on the matter. Now men ought to have sunk their speculations for awhile, and inquired what that is which is common to all lucid bodies; in other words, into the Form of Light. For see what an immense difference of body there is (if they be considered according to their dignity) between the sun and rotten wood, or even the putrified scales of fish? They should also have inquired why some things take fire and throw out light when heated, and others not. Iron, metals, stones, glass, wood, oil, tallow, when they are subjected to fire, either break into flame, or at least become red; but water and air do not acquire any light from the most intense and raging heat, nor cast forth any brightness. And if any one thinks that this