BOOK II.] APHORISMS. 477 



notion of elementary and celestial nature, and rarity, are vague 

 and ill-defined. We, therefore, who are neither ignorant nor 

 forgetful of the great work which we attempt, in rendering the 

 human understanding adequate to things and nature, by no means 

 rest satisfied with what we have hitherto enforced, but push 

 the matter farther, and contrive and prepare more powerful aid 

 for the use of the understanding, which we will next subjoin. 

 And, indeed, in the interpretation of nature the mind is to be so 

 prepared and formed, as to rest itself on proper degrees of cer 

 tainty, and yet to remember (especially at first) that what is 

 present depends much upon what remains behind. 



XX. Since, however, truth emerges more readily from error 

 than confusion, we consider it useful to leave the understanding 

 at liberty to exert itself and attempt the interpretation of nature 

 in the affirmative, after having constructed and weighed the 

 three tables of preparation, such as we have laid them down, 

 both from the instances there collected, and others occurring 

 elsewhere. Which attempt we are wont to call the liberty of 

 the understanding, or the commencement of interpretation, or 

 the first vintage. 



The First Vintage of tlie Form, of Heat. 



It must be observed that the form of anything is inherent (as 

 appears clearly from our premises) in each individual instance in 

 which the thing itself is inherent, or it would not be a form. No 

 contradictory instance, therefore, can be alleged. The form, 

 however, is found to be much more conspicuous and evident in 

 some instances than in others ; in those (for example) where its 

 nature is less restrained and embarrassed, and reduced to rule by 

 other natures. Such instances we are wont to term coruscations, 

 or conspicuous instances. We must proceed, then, to the first 

 vintage of the form of heat. 



From the instances taken collectively, as well as singly, the 

 nature whose limit is heat appears to be motion. This is chiefly 

 exhibited in flame, which is in constant motion, and in warm or 

 boiling liquids, which are likewise in constant motion. It is also 

 shown in the excitement or increase of heat by motion, as by 

 bellows and draughts: for which see Inst. 29, Tab. 3, and by 

 other species of motion, as in Inst. 28 and 31, Tab. 3. It is also 

 shown by the extinction of fire and heat upon any strong pres 

 sure, which restrains and puts a stop to motion ; for which see 

 Inst. 30 and 32, Tab. 3. It is further shown by this circumstance, 

 namely, that every substance is destroyed, or at least materially 

 changed, by| strong and powerful fire and heat : whence it is 

 clear that tumult and confusion are occasioned by heat, together 

 with a violent motion in the internal parts of bodies; and this 

 gradually tends to the a: dissolution. 



