The Common Principles of Natural Philosophy

essence is said to be in potentiality for the production of water, 5 a 1. and it is the material principle in the generation of water and the corruptionoriginal: "corrupcione"; in medieval science, this refers to the passing away or destruction of a form, the opposite of generation. of earth. And thus it is in other things generated by nature. If indeed matter is spoken of in other ways, it will be made clear below, but especially in the Metaphysicsoriginal: "Methaphisica"; Aristotle's work on the first principles of things., and all these things will shine forth more clearly in their proper places.

Second Distinction: Concerning that which is produced by an agent in matter.

Chapter One.

Having established that two things are required for the production of things—namely, the efficient causeoriginal: "efficiens"; the active force or entity that brings about a change. and matter—we must now proceed concerning the efficient cause as much as is required here, because Metaphysics has the task of fully certifying the influence of agents upon patientsoriginal: "paciencia"; the thing or matter that receives the action of an agent., for the reason that every operation upon the senses, the intellect, F. 86 a 1. and the matter of the world occurs

through influences of this kind—namely, those aforementioned things which are called speciesoriginal: "species"; a central concept for Bacon, referring to the "likeness" or "force" emitted by an object (like light or heat) through which it acts on its surroundings.. Therefore, all things are certified through them; for this reason, it belongs to that universal science common to all things to treat of such matters according to the fullness of its power.

Now, the efficient cause always intends the patient and the matter to become like itself; for this reason it acts, since diversity cannot be created unless identityoriginal: "ydemptitate"; sameness or likeness between the cause and the effect. precedes it, nor is a multitude created except from unity. Therefore, if light generates heat in the air, it must first generate light; and if fire induces death, it must first produce fire in that which succumbs to death. The first effect of an agent, therefore, is to generate something similar to itself, as light produces light; and this generation is called univocaloriginal: "univoca"; when a cause produces an effect of the same nature as itself., because one similar nature is preserved in both the generator and the generated. The second effect is different, as when light produces heat; and this generation is called equivocaloriginal: "equivoca"; when a cause produces an effect of a different nature from itself. because of the diversity between the generator and the generated.

We must now speak, therefore, of that first effect which is called the Power of the Agentoriginal: "Virtus Agentis"; the active capacity of a thing to exert influence., and the Likeness, and the Speciesoriginal: "Species"; here used as the technical term for the transmission of an object's form., and the Image, and by many other names, as is taught in metaphysical works; just as light in the air is the likeness of the light in the sun or a star. For the species of light is visible, 5 a 2. but the species of other things are not seen

except in some particular case, such as the species of a strong color in glass and crystal, or in a cloth well...