5 2 VITAL FORCE, INSTINCT, AND SENSATION. 



moist earth, the protoplasm in the majority of cases begins to bestir itself and 

 to move, and the embryo grows out into a seedling. After twenty years, perhaps, 

 only about five per cent of the seeds preserved would germinate. The rest are not 

 stimulated by damp earth to further development; their protoplasm no longer 

 possesses the power of augmenting its volume by absorption of matter from the 

 environment, or of developing a definite form, but is disintegrated by the influx of 

 air and water and breaks up into simpler compounds. After thirty years hardly 

 one of the seeds would sprout. Yet all these seeds were kept throughout the time 

 at one place and under precisely the same external conditions; nor can the slightest 

 change in their appearance be detected. Gardeners express the fact by saying that 

 the capacity for germination becomes extinct in from twenty to thirty years. But 

 what kind of a force is this which may perish without a physical change of the 

 substance concerned affording the basis of the extinction? In former times a special 

 force was assumed, the force of life. More recently, when many phenomena of plant 

 life had been successfully reduced to simple chemical and mechanical processes, 

 this vital force was derided and effaced from the list of natural agencies. But by 

 what name shall we now designate that force in nature which is liable to perish 

 whilst the protoplasm suffers no physical alteration and in the absence of any 

 extrinsic cause; and which yet, so long as it is not extinct, causes the protoplasm 

 to move, to inclose itself, to assimilate certain kinds of fresh matter coming 

 within the sphere of its activity and to reject others, and which, when in full 

 action, makes the protoplasm adapt its movements under external stimulation to 

 existing conditions in the manner which is most expedient? 



This force in nature is not electricity nor magnetism; it is not identical with 

 any other natural force, for it manifests a series of characteristic effects which 

 differ from those of all other forms of energy. Therefore, I do not hesitate again 

 to designate as vital force this natural agency, not to be identified with any other, 

 whose immediate instrument is the protoplasm, and whose peculiar effects we 

 call life. The atoms and molecules of protoplasm only fulfil the functions which 

 constitute life so long as they are swayed by this vital force. If its dominion 

 ceases, they yield to the operations of other forces. The recognition of a special 

 natural force of this kind is not inconsistent with the fact that living bodies 

 may at the same time be subject to other natural forces. Many phenomena of 

 plant life may, as has been already frequently remarked, be conceived as simple 

 chemical and mechanical processes, without the introduction of a special vital 

 force; but the effects of these other forces are observed in lifeless bodies as well, 

 and indeed act upon them in a precisely similar manner, and this cannot be said 

 of the force of life. 



Were we to designate as instinctive those actions of the vital force which 

 are manifested by movements purposely adapted in some manner advantageous 

 to the whole organism, nothing could be urged against it. For what is instinct 

 but an unconscious and purposeful action on the part of a living organism? Plants, 

 then, possess instinct. We have instances of its operation in every swarm-spore 



