338 THE POPULAR SCIENCE MONTHLY. 



highest places of knowledge. That was not Bacon's notion of it : he 

 perceived clearly enough that a man does not see with his eye, but 

 through it ; that seeing in the sense of observation is impossible unless 

 there be behind the eye the intelligence to interpret what is presented 

 to it. The simplest act of perception is indeed more than a mere 

 matter of sense ; it is an actual induction or inference in which an 

 important element is contributed by the mind ; you cannot look at an 

 ox or an ass, and know either of them to be what it is, without making 

 an induction can't see, in fact, until you are trained to see. Scientific 

 observation and experimentation and experiment is only observation 

 aided by artificial means may be carried on to the last hour of your 

 lives without any result of the least value if you have not a mind 

 trained to interpret. Of what use is it to torture Nature by strange 

 experiments if you don't understand her language ? You might sacri- 

 fice a hundred dogs or cats in cruel experiments, and be not a whit 

 wiser at the end of your awful labors. Nature does not vouchsafe an 

 answer to a scientific inquiry unless the intelligent question be put, 

 and the precise experiment made, as Bacon insisted, ad intentionem 

 ejus quod quceritur; ' and it is impossible to put the definite question, 

 or to make the precise experiment, unless there be a prudently-formed 

 hypothesis in the mind that is to say, an hypothesis based upon pre- 

 vious careful training in observation of Nature's processes and sound 

 reflection upon them. The mind must be informed by patient and 

 sympathetic intercourse with Nature ; it is enabled then to make new 

 adjustments by means of the knowledge which it has gained through 

 past adjustments to frame a new and true theory applicable to new 

 experiences by reason of being stored with sound theories derived 

 from past experiences. We shall do well, then, not to be too much 

 intimidated by what is sometimes said or written in praise of mere 

 observation of so-called facts, and in dispraise of theory, or imagine 

 that any facts can be truly observed, or any science prosecuted with 

 success, unless the well-trained mind cooperates with the senses. As 

 I have said elsewhere, " That some declaim so virulently against 

 theory is as though the eunuch should declaim against lechery ; it is 

 the chastity of impotence." Happy is the observer who, when he sets 

 to work, has a good theory in his mind. The mischief is when men 

 theorize who have not been trained in habits of accurate observation, 

 or, I might go a step further and say, who have not inherited from 

 father or grandfather in the foundations of their nature the lines of 

 veracity of observation and thought on which to develop ; for when 

 one notices how persons of a certain eager temperament go on dis- 

 covering facts which are no facts, and, notwithstanding that they are 

 brayed in the mortar of an annihilating criticism, are not in the least 

 benefited by the discipline, one cannot help feeling that the observer, 

 like the poet, is born, not made. 



1 With special reference to the point under investigation. 



