39 o BACON 



IX. On account of air, which is generally found to be cold and yet 

 continues rare, reject rarity. 



X On account of ignited iron, which does not swell in bulk, but 

 retains the same apparent dimension, reject the absolute expansive 

 motion of the whole. 



XI. On account of the expansion of the air in thermometers and 

 the like, which is absolutely moved and expanded to the eye, and yet 

 acquires no manifest increase of heat, again reject absolute or ex- 

 pansive motion of the whole. 



XII. On account of the ready application of heat to all substances 

 without any destruction or remarkable alteration of them, reject de- 

 structive nature or the violent communication of any new nature. 



XIII. On account of the agreement and conformity of the effects 

 produced by cold and heat, reject both expansive and contracting mo- 

 tion as regards the whole. 



XIV. On account of the heat excited by friction, reject principal 

 nature, by which we mean that which exists positively, and is not 

 caused by a preceding nature. 



There are other natures to be rejected; but we are merely offering 

 examples, and not perfect tables. 



None of the above natures is of the form of heat ; and man is freed 

 from them all in his operation upon heat. 



19. In the exclusive table are laid the foundations of true in- 

 duction, which is not, however, completed until the affirmative 

 be attained. Nor is the exclusive table perfect, nor can it be 

 so at first. For it is clearly a rejection of simple natures ; but 

 if we have not as yet good and just notions of simple natures, 

 how can the exclusive table be made correct? Some of the 

 above, as the 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 at- 

 tempt, 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 certainty, and yet to remember (es- 

 pecially at first) that what is present depends much upon what 

 remains behind. 



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

 than confusion, we consider it useful to leave the understand- 

 ing 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. 



