Question: What's up with hemalurgy and feruchemy? / What's up with heat being mental feruchemy/ What's up with the feruchemical attribute quadrants? Answer: Long story short, the quadrants originally lined up, but Brandon accidentally swapped a couple feruchemical metals in Mistborn. The rest of the metals in the system got revised, so it's now realmatically aligned instead of quadrant...ly. Hence, there are eight physical, four cognitive, and four spiritual feruchemical abilities - that means a pewter spike can steal one of EIGHT feruchemical abilities, which is pretty nifty. Source: Word of Brandon http://www.theoryland.com/intvmain.php?i=839
http://www.theoryland.com/intvmain.php?i=689