64 THE POPULAR SCIENCE MONTHLY, 



genetic inferences, with the evil accompaniment of eager welcome 

 for facts which agree with the favorite phylogenetic theories of 

 the day, and of disdain for such facts as did not concord with 

 these theories. Thus has been created that biological mythology 

 against which Prof. E. B. Wilson has protested so suitably. 



Philosophy and science are practically often incompatible not 

 because philosophy is unworthy of our entire respect, but because 

 would-be philosophers are not seekers for wisdom but lovers of 

 speculation. Twenty years ago we thought that Oken, whose 

 Natur-philosophie was created by his speculative enthusiasm, 

 would never have another imitator, but since then biological spec- 

 ulation has become almost a fetich. Let us part company from 

 the horde of foolish thoughts which have too long masqueraded 

 under the false garb of philosophy. For our lifetimes the labor 

 of inductive research will suffice, and we may well leave deduc- 

 tion for future generations. Philosophy, so called, is often an 

 effort to decide what must be, but while knowledge remains im- 

 perfect the " must be's " will guide us wrong more frequently 

 than they will guide us aright. As long as Science seeks to deter- 

 mine what is, her work will endure. My protest against specula- 

 tion is no idle rhetoric, for the evil is very great. I hope that 

 Weismann's mystical treatise on Germplasm will prove to be the 

 culminating effort of the speculative school, and that the influ- 

 ence of the school will be as brief as it has been widespread. 



A hypothesis may be a good serving maid to clean away rub- 

 bish and get the workroom in order. It is for us to remember 

 that this good maid makes the worst mistress. 



There are many other difficulties of character which obstruct 

 reason, but you will excuse me from an exhaustive review of 

 them, and therefore I will refer only to one more, and that briefly. 

 I mean the artistic perception which induces us to look for com- 

 pleteness, clearness, and simplicity, so that we are tempted to add 

 a little or more to our conclusions, or to accept a result partly be- 

 cause it is complete, clear, and simple. The most eminent illus- 

 tration of this tendency is Herbert Spencer, whose mental pro- 

 cesses are so far governed by his love of clear, simple formulae 

 that he uses simplicity as a test of his conclusions, and makes 

 formulation a test of truth and a substitute for proof. We are 

 all inclined to be lax as to our proofs if the generalization is satis- 

 factory and pleasing, but Spencer's mistakes may warn us against 

 the danger of gratifying this inclination. Science is not one of 

 the fine arts. Its work can not be directed by the love of beauty 

 or by sentiments. Science is a pursuit for the intellect and for 

 the intellect alone. 



I will turn to another part of our work publication. Scien- 

 tific publications naturally group themselves in four classes : origi- 



