You mean because such seeking "would bring madness & vexation to anyone who conjectured about it"? Why do you accept these reasons (or whatever reasons they give if you do not mean the above)? I thought Karma was a fundamental doctrine of Buddhism? Most web-searches on the matter certainly suggest so, such as http://www.blia.org/english/publications/booklet/pages/06.htm (and this is just one of many). How so? What is the difference? Where does the analogy fall down? Or is it just because Buddhist teachings say so, along the lines of "Buddha is different... 'cos it says so... and don't ask why, 'cos that way madness lies... again because it says so!"