Febeuaby 21, 1896.] 



SCIENCE. 



265 



and this is the sole case where we have a 

 term for an illusion which is commonly 

 understood in that sense, but the term 

 spirit is used in both senses, for the certi- 

 tude and for the illusion. 



The seven illusions here enumerated are 

 perhaps the most fundamental and far- 

 reaching of the vast multitude of illusions 

 •which appear in the history of error. The 

 words substrate, essence, space, force, time, 

 ghost and cause are terms of universal use 

 and their synonyms appear in all civilized 

 languages, and perhaps in all lower lan- 

 guages. They have always stood for cer- 

 titudes and illusions ; here they require de- 

 finitions both as certitudes and as illu- 

 sions, in so far as we are able to define 

 them. 



SUBSTRATE. 



Substrate is matter, matter is the sub" 

 strate of all bodies. Essence is any collo- 

 cation of units into a unit of a higher order 

 which makes it a kind or one of a class- 

 Space is any extension or any collocation of 

 extensions; force is any collocation of mo- 

 tions that are related by collisions; time is 

 any duration or collocation of durations; 

 mind or spirit or ghost is any cognition or 

 ■collocation of cognitions; cause is any re- 

 lated antecedent or collocation of such 

 antecedents of a change. Such are the 

 fundamental meanings of the words when 

 used to designate realities. We shall here- 

 after see what they mean when they are 

 used to designate illusions. Matter is the 

 :substrate of body and has no substrate for 

 itself. All matter has four factors or constit- 

 uents, number, extension, motion and 

 duration, and some matter at least has a 

 fifth factor, namely judgment. Matter is not 

 a substrate for these factors, but exists in 

 these constituents which are never dissoci- 

 -ated, but constitute matter, or are the mo- 

 ments of matter; and this matter is the 

 substrate of all bodies. 



ESSENCE. 



The term essence as used in philosophy 

 is employed in a double manner and is thus 

 often ambiguous. It is sometimes used as 

 a synonym for substrate of matter, at other 

 times it is used to designate the occult sub- 

 strate of class. In this latter sense it is here 

 used. Essence, then, is the number essen- 

 tial to make an order or kind of a class. As 

 the whole number is essential, every one is 

 essential; they are severally and conjointly 

 essential, so that it is possible correctly to 

 speak of them all as being essential and to 

 speak of every one severally as being essen- 

 tial. All of the particles which make up a 

 body are conjointly and severally essential 

 to that body, and the essence of a body is 

 the hierarchy of particles of which it is com- 

 posed. The term essence, therefore, is a 

 general term or pronoun for all collocations 

 of number, and its special meaning is de- 

 rived from the context. As an illusion, 

 essence is the name of an unknown some- 

 thing which produces a kind or class, and 

 is a property of an unknown or unknowable 

 substrate of matter. 



If, as the chemist believes, with much 

 good reason, the ultimate chemical particles 

 are alike, they are alike only in number, 

 extension, motion and duration ; they are 

 unlike in association, position, direction or 

 motion and the duration of association, so 

 that likeness and unlikeness is inherent in 

 matter itself. In bodies innumerable com- 

 binations of number, extension, motion and 

 duration are found, and out of these are de- 

 veloped innumerable likenesses and unlike- 

 nesses, so that one body is like another in 

 many respects and unlike that other in many 

 other respects. The science of classifica- 

 tion takes these likenesses and unlikenesses 

 and discovers degrees among them which 

 are of profound importance in the study of 

 the world, and upon which a large share of 

 knowledge rests. All knowledge does not 

 rest upon likeness and unlikeness ; but like- 



