VUl 



CHAPTER IV. 

 Of Laws of Nature. 

 (l 1. The general regularity in nature is 

 a tissue of partial regularities, call- 

 ed laws 189 



2. Scientific induction must be ground- 



ed upon previous spontaneous in- 

 ductions 191 



3. Are there any inductions fitted to be 



a test of all others ? . . .192 



CHAPTER V. 

 Of the Law of Universal Caxisation. 



^ 1. Theuniversallawof successive phe- 

 nomena is the Law of Causation . 194 



2. — i. e. the law that every consequent 



has an invariable antecedent . 196 



3. The cause of a phenomenon is the 



assemblage of its conditions . . 197 



4. The distinction of agent and patient 



illusory 201 



5. The cause is not the invariable ante- 



cedent, Ijut the unconditional invari- 

 able antecedent .... 202 



6. Can a cause be simultaneous with 



its effect ? 204 



7. Idea of a Permanent Cause, or ori- 



ginal natural agent . . . 206 



8. Uniformities of coexistence between 



effects of different permanent 

 causes, are not laws . . . 208 



9. M. Comte's objections to the word 



cause 209 



CHAPTER VI. 



Of ihe Compositimi of Causes. 



ij 1. Two modes of the conjunct action 

 of causes, the arechanical and the 

 chemical 210 



2. The composition of causes the gen- 



eral rule ; the other case excep- 

 tional 212 



3. Are effects proportional to their 



causes? 214 



CHAPTER Vn. 



Of Observation and Experiment. 



^ 1. The first step of inductive inquiry is 

 a mental analysis of complex phe- 

 nomena into their elements . . 216 



2. The next is an actual separation of 



those elements .... 217 



3. Advantages of experiment over ob- 



servation 218 



4. Advantages of observation over ex- 



periment 220 



CHAPTER VIII. 



Of the Four Methods of Experimental Inqxary. 



(j 1. Method of Agreement . . . 222 



2. Method of Difference . . .224 



3. Mutual relation of these two meth- 



ods 225 



4. Joint Method of Agreement and Dif- 



ference 227 



5. Method of Residues . . .229 



6. Method of Concomitant Variations . 230 



7. Limitations of this last method . 234 



Page 



CHAPTER IX. 



Miscellaneous Examples of the Fowr Methods. 

 (} 1. Liebig's theory of metallic poisons . 237 



2. — how far a perfect example . . 239 



3. Theory of induced electricity . . 240 



4. Dr. Wells' theory of dew . . .242 



5. Examples ofthe Method of Residues 247 



CHAPTER X. 

 Of Plurality of Causes ; and of the Intermixture 



of Effects. 

 () 1. One effect may have several causes 250 



2. — which is the source of a character- 



istic imperfection of the Method of 

 Agreement 251 



3. Plurahty of Causes, how ascertained 253 



4. Concurrence of causes which do not 



compound their effects . . . 254 



5. Difiiculties of the investigation, 



when causes compound their ef- 

 fects 256 



0. Three modes of investigating the 

 laws of complex effects . . 259 



7. The method of simple observation 



inapplicable 260 



8. The purely experimental method in- 



applicable 261 



CHAPTER XL 

 Of the Deductive Method. 

 ^ 1. First stage ; ascertainment of ttie 

 laws of the separate causes by di- 

 rect induction .... 264 



2. Second stage ; ratiocination from 



the simple laws to the complex 

 cases 267 



3. Third stage ; verification by specific 



experience . . . . . 268 



CHAPTER XII. 



Of the Explanation of Laws of Nature. 



9 1. Explanation defined . . . 271 



2. First mode of explanation, by resolv- 



ing the law of a complex effect into 

 the laws of the concurrent causes 

 and the fact of their coexistence . ib. 



3. Second mode; by the detection of an 



intermediate link in the sequence . 272 



4. Laws are always resolved into laws 



more general than themselves . ib. 



5. Third mode ; the subsumption of 



less general laws under a more 

 general one . . . . 274 



6. What the explanation of a law of 



nature amounts to . . . . 276 



CHAPTER Xni. 

 Miscellaneous Examples of the Explanation of 



Laws of Nature, 

 (j 1. Liebig's theory' of the contagious- 

 ness of chemical action . .277 



2. His theory of respiration . . . 280 



3. Other speculations of Liebig . • 282 



4. Examples of following newly-dis- 



covered laws into their complex 

 manifestations .... 283 



5. Examples of empirical generaliza- 



tions, afterwards confirmed and 

 explained deductively . . . 284 



6. Example from mental science . . 285 



