1 32 HISTORY OF SCIENCE. 



Bacon aimed his blows belong not more to the temple of science than 

 to the inner sanctuary of the human mind. Seekers after knowledge 

 in other regions than that of physical science have often paid to the 

 idols the homage which ought to have been offered only at the shrine 

 of truth ; and the history of science in times past, as well as in our 

 own, will often show us the honest inquirer unconsciously bowing the 

 knee to one or other of the false images. 



The idols of the tribe (idola tribus) are so named because they are 

 common to the whole tribe or race of mankind, inasmuch as they 

 arise from the very nature of the human understanding. Our author 

 illustrates his meaning by a beautiful simile, rising almost into poetry : 

 " The understanding of man is like a mirror whose surface is not true, 

 and so mixing its own imperfection with the nature of things, it distorts 

 and perverts them." He instances our tendency to expect in nature 

 uniformities and correspondences, which are in reality only the re- 

 flections of our own conceptions. Thus the ancient astronomers sup- 

 posed that the planets must move in perfect circles and with uniform 

 velocity, and strove hard to reconcile their observations with this gra- 

 tuitous assumption. Many current axioms it may here be remarked 

 are in reality fallacies arising from our assuming that the order of 

 our ideas must be the order of nature, or, in other words, supposing 

 that the subjective laws which obtain in our own mind apply likewise 

 to the world of external things. Such are the sayings : "Nature always 

 acts by the simplest means ;" "whatever can be thought of apart exists 

 apart ; " <; a thing cannot act where it is not." Of this nature, perhaps, 

 was the fallacy which led Plato to ascribe real external existence to 

 the mental abstractions he called " the Ideas." The tendency which 

 stili so often misleads men of science into subordinating the true in- 

 terpretation of facts to a well-rounded symmetrical system may be 

 ranked under this head. To the idols of the tribe belong also those 

 prepossessions with regard to some favourite notion; as when men 

 have perceived in the fulfilment of dreams, prophecies, and astrological 

 predictions, a confirmation of the validity of such things, because they 

 have simply overlooked the far more numerous cases in which no 

 fulfilment took place. Another cause of error mentioned by Bacon 

 under this head is the influence of the feelings on the will and the 

 intellect. " The light of the understanding/' he says, " is not a dry 

 or pure light, but it receives a tincture from the will and the affections; 

 and it forms the sciences accordingly, for men are most willing to 

 believe what they most desire." In the restless activity which prompts 

 our minds to grasp at what is beyond their power lies another source 

 of our errors. We weary our understandings with attempts to com- 

 prehend such ideas as space, time, eternity, and infinity, and by seek- 

 ing to discover uses, ends, or final causes of things. The tendency 

 of the mind towards abstractions and generalizations is also mentioned 



