No. XVII. A.] APPENDIX. 271 



Infinity. 



13. An idea is represented from the excitement of one or all the 

 nervous fibrils of any organ of sensation indiscriminately. This idea is 

 infinite, inasmuch as it is indivisible, incapable of addition and represents 

 totality.* 



Time. 



14. Our knowledge of the external world at any given period is the 

 sum total of the images from all our senses. 



15. These images represented to the mind are perpetually changing. 



16. When images change, one remains; the other changes perhaps 

 several times before the first changes. The relation of these changes to 

 each other is termed the time of their occurrence ; that which changes the 

 least frequently is said to be of the longest duration. 



Cause. 



17. In the change of images, when one specific image never appears 

 without a similar antecedent, and the matter in the external world which 

 gave rise to the first image set in motion the second the antecedent 

 image is said to cause the second image. 



18. The mind finds great difficulty in distinguishing between con- 

 comitance and cause, because the matter which produces an antecedent 

 image may not set in motion the matter which produced the second image. 



Pleasure and Pain. 



19. When images of the external world are produced with a certain 

 intensity, the idea of Pleasure is excited ; when with a greater intensity, 

 the idea of Pam.f 



20. The transition from Pleasure to Pain being sudden, not gradual, 

 it follows that the nature of the action on the brain, and consequently of 

 the ideas, is different. 



Memory. 



21. An image once formed in the brain produces an indelible impres- 

 sion, and may at any future time recur. This property is called Memory. 



Consciousness. 



22. When an image is produced by an action upon the external senses, 

 the actions on the organs of sense concur with the actions in the brain ; 

 and the image is then a Reality. 



23. When an image occurs to the mind without a corresponding 

 simultaneous action of the body, it is called a Thought. 



24. The power to distinguish between a thought and a reality is 

 called Consciousness. 



* Infinity is sometimes confounded with its hyperbolical use in the sense of 

 endless number. 



t Every action of our lives is either pleasurable or painful ; and thus we 

 perceive how vastly the former state preponderates over the latter. 



