Bishop Butler's celebrated argument on the immortality of the soul is founded entirely on this principle. It is briefly this:
Things will continue as they are and have been unless there is some evidence of some change or cause for a change. At death the soul exists. The dissolution of the body is no evidence of the destruction of the soul, and there is no kind of evidence that it is destroyed. Therefore we infer that the soul continues to exist after the dissolution of the body.
The main point in this argument is to show that there is no evidence that the act of death involves the destruction of the soul. If this can be established, then the belief must follow that the soul exists after death. By the same method Butler establishes several other doctrines of the Bible.
It is by the aid of this principle that what are called the laws of nature are established. By means of human testimony we learn what has been the uniform course of nature. And then men conclude that what has been will continue to be until some new cause intervenes to change this uniformity.
The seventh intuitive truth is, that the NEEDLESS DESTRUCTION OF HAPPINESS OR INFLICTION OF PAIN IS WRONG, and THAT WHATEVER TENDS TO PRODUCE THE MOST HAPPINESS IS RIGHT.
The terms right and wrong, as used by mankind, always have reference to some plan or design. Any thing is called right when it fulfills the design for which it is made, and it is called wrong when it does not. Thus a watch is right when it fulfills its design in keeping time. A compass is right when it points to the north. And so of all contrivances.
Of course, then, the question as to the right and wrong action of mind involves a reference to the object or design of the Author of mind. At this time it will be assumed (the proof being reserved for future pages) that the design or object for which God made mind was to produce the greatest possible happiness with the least possible evil.
It is also assumed, without here exhibiting the proof, that the impression of this design is so inwrought into the mental constitution that whatever is perceived to be destructive to happiness is felt to be wrong—that is, unfitted to the design of the Author of all things, which the mind feels often when it can not logically set forth the reason. So, also, whatever is seen to promote the greatest amount of happiness is felt to be right.
The mind is so constituted that, without any act of reasoning as to the tendencies of things, there are certain feelings and actions that the mind turns from as unfit and to be abhorred.
Thus, when plighted faith is violated, or a great benefactor treated with cruelty and indignity by those he has benefited, a feeling of unfitness and abhorrence is awakened, independent of all considerations of the tendency of such conduct to destroy happiness.