SO GENERAL PREFACE TO 



of the motion or arrangement, or of whatever else may be the 

 Form of a given phenomenon, takes the shape of a law ; it is the 

 law in fulfilling which any substance determines the existence 

 of the quality in question. It is for this reason that Bacon 

 sometimes calls the Form a law ; he has done this particularly 

 in a passage which will be mentioned a little farther on. 



With the view which has now been stated, we shall I think 

 be able to understand every passage in which Bacon speaks of 

 Forms ; remembering however that as he has not traced a 

 boundary line between primary and secondary qualities, we can J 

 only say in general terms that his doctrine of Forms is founded 

 upon the theory that certain qualities of bodies are merely sub- 

 jective and phenomenal, and are to be regarded as necessarily 

 resulting from others which belong to substance as its essential ' 

 attributes. In the passage from which we set out 1 , the Form is 

 spoken of as vera differentia, the true or essential difference, as 

 natura naturans and as the fons emanationis. The first of 

 these expressions refers to the theory of definition by genus and 

 difference. The difference is that which gives the thing defined 

 its specific character. If it be founded on an accidental circum- 

 stance, the definition, though not incorrect if the accident be an 

 inseparable one, will nevertheless not express the true and 

 essential character of its subject; contrariwise, if it involve a 

 statement of the formal cause of the thing defined. 



The second of these phrases is now scarcely used, except in 

 connexion with the philosophy of Spinoza. It had however 

 been employed by some of the scholastic writers. 2 It is always 

 antithetical to natura naturata, and in the passage before us 

 serves not inaptly to express the relation in which the Form 

 stands to the phenomenal nature which results from it. 



The phrase fons emanationis does not seem to require any 

 explanation. It belongs to the kind of philosophical language 

 which attempts, more or less successfully, to give clearness of 

 conception by means of metaphor. It is unnecessary to remark 

 how much this is the case in the later development of scho- 

 lasticism. 



A little farther on in the second book of the Novum Or- 

 ganum than the passage we have been considering, namely 



1 [Nov. Org. ii. 1.] 



2 See Vossius De Vitiis Serm. in voce Naturare ; and Castanaeus, Distinctiones in 

 voc. Natura. 



