LAW OF CAUSATION. 199 



any of them which may not, according to the purpose of our immediate 

 discourse, obtain that nominal preeminence. This will be seen by 

 analyzing the conditions of some one familiar phenomenon. For 

 example, a stone thrown into water falls to the bottom. What are the 

 conditions of this event] In the first place there must be a stone, and 

 water, and the stone must be thrown into the water ; but, these suppo- 

 sitions forming part of the enunciation of the phenomenon itself, to 

 include them also among the conditions would be a vicious tautology, 

 and this class of conditions, therefore, have never received the name of 

 cause from any but the schoolmen, by whom they were called the ma- 

 terial cause, causa materialis. The next condition is, there must be 

 an earth : and accordingly it is often said, that the fall of a stone is 

 caused by the earth ; or by a power or property of the earth, or a force 

 exerted by the earth, all of which are merely roundabout ways of say- 

 ing that it is caused by the earth ; or, lastly, the earth's atti-action; which 

 also is only a technical mode of saying that the earth causes the motion, 

 with the additional particularity that the motion is towards the earth, 

 which is not a character of the cause, but of the effect. Let us now 

 pass to another condition. It is not enough that the earth should exist; 

 the body must be within that distance fi'om it, in which the earth's 

 attraction preponderates over that of any other body. Accordingly we 

 may say, and the expression would be confessedly correct, that the 

 cause of the stone's falling is its being within the sphere of the earth's 

 attraction. We proceed to a further condition. The stone is immersed 

 in water : it is therefore a condition of its reaching the ground, that its 

 specific gravity exceed that of the surrounding fluid, or in other woi'ds 

 that it surpass in weight an equal volume of water. Accordingly, any 

 one would be acknowledged to speak correctly who said, that the cause 

 of the stone's going to the bottom is its exceeding in specific gravity 

 the fluid in which it is immersed. 



Thus we see that each and every condition of the phenomenon may 

 be taken in its turn, and with equal propriety in common parlance, but 

 with equal impropriety in scientific discourse may be spoken of as if 

 it were the entire cause. And in practice that particular condition is 

 usually styled the cause, whose share in the matter is superficially the 

 most conspicuous, or whose requisiteness to the production of the effect 

 we happen to be insisting upon at the moment. So great is the force 

 of this last consideration, that it often induces us to give the name of 

 cause even to one of the negative conditions. We say, for example, 

 The cause of the army's being surprised was the sentinel's being oft' 

 his post. But since the sentinel's absence was not what created the 

 enemy, or made the soldiers to be asleep, how did it cause them to be 

 surprised ? All that is really meant is, that the event would not have 

 happened if he had been at his duty. His being off his post was no 

 producing cause, but the mere absence (^ a preventing cause : it was 

 simply equivalent to his non-existence. From nothing, from a mere 

 negation, no consequences can proceed. All effects are connected, by 

 the law of causation, with some set oi positive conditions ; negative ones, 

 it is true, being almost always required in addition. In other words, 

 every fact or phenomenon which has a beginning, invariably arises 

 when some certain combination of positive facts exists, provided cer- 

 tain other positive facts do not exist. 



Since, then, mankind are accustomed, with acknowledged propriety 



