DIFFERENCES BETWEEN ANIMALS AND PLANTS. 31 



The tenacity with which many thinkers still cling to a belief in the 

 reality and absoluteness of such distinctions as those expressed by the 

 terms "organic and inorganic," "living and dead," "animal and vege- 

 table," " rational and instinctive," etc., is plainly the result of this ten- 

 dency to attribute to Nature the exactness of words. 



The terms animal and plant were not established as the result of 

 scientific and thorough study and comparison, but were first introduced 

 to give expression to the most superficial and obvious difference be- 

 tween living things. 



Originally an animal was a living thing which could move and feel, 

 and a plant one which could not ; and this is still the popular view, 

 although the scientific definitions are quite different. As soon as prim- 

 itive man began to observe and to generalize and to use abstract 

 words, one of the first generalizations which attracted his attention 

 was that, of the bodies which were of most importance to him, and like 

 him grew up, matured, and died, some were still more like hipiself in 

 having the power to move and feel, while others lacked this power, and 

 were fixed and insensible. We do not intend to imply that this gener- 

 alization took this definite shape, but simply that it was reached and 

 put into words at a very early period; and this is shown by the fact 

 that in nearly all languages, and among all but the lowest races of 

 men, this division of living things into two great groups is recognized, 

 and definite words are employed to distinguish the animal from the 

 vegetable organism. At a later period, when living things came to be 

 more carefully studied, and superficial observation gave place to more 

 exact and careful comparison, these two groups were found to have a 

 real existence in Nature ; and, as long as this study was confined to the 

 more familiar, abundant, and easily-studied organisms, the increase of 

 scientific knowledge only served to render the distinctness of the two 

 groups more evident. It was soon found that all the common plants 

 are alike in many other respects besides being fixed and insensible, and 

 that all ordinary animals have many common characteristics, and it was 

 found convenient to express these resemblances briefly and absolutely 

 in definitions, and thus the terms animal and plant came to have a 

 more and more exact and scientific value. It was seen, too, that all 

 living things have much in common, and that the chief difference be- 

 tween plants and animals is the possession by the latter of the new 

 properties of sensation and voluntary motion, added to those character- 

 istics which they share with the plants. It is not at all strange that it 

 was thought desirable to express this fact by a word, and that, in the 

 same way that living things were said to differ from inorganic bodies 

 by having, in addition to all the properties of the latter, a new and 

 higher quality, vitality, animals were said to possess the new and 

 higher faculties of feeling and will, in addition to all the faculties of 

 the plant. 



Thus was gradually built up that conception of Nature which re- 



