question: What are the three things John Herschel maintains need to be shown to allow for a mechanism be called a true cause ?
answer: its existence in nature , its ability to produce the effects of interest , and its ability to explain a wide range of observations
turker_answer: The three things John Herschel maintains need to be shown to allow for a mechanism to be called a true cause is its existence in nature , its ability to produce the effects of interest , and its ability to explain a wide range of observations .
rule-based: Its existence in nature , its ability to produce the effects of interest , and its ability to explain a wide range of observations are the three things John Herschel maintains need to be shown to allow for a mechanism be called a true cause .