 We have introduced the issue of computational (or algorithmic) irreducibility when we explained the philosophical consequence of a universality proof for an automaton, namely that, although a system follows definite underlying laws, “its overall behavior can still have aspects that fundamentally cannot be described by reasonable laws” (Wolfram 2002: 750). This is again the issue of predictability via step by step micro-computations. In this “separation between the underlying rules for the system and its overall behavior” (Wolfram 2002: 751) lies the secret of free will, since it seems that we attribute free will to a system just when “we cannot readily make predictions about the behavior of the system” (Wolfram 2002: 751). According to Wolfram, CA play a leading role in providing a new framework to understand the phenomenon. While explanations from chaos theory and quantum randomness have recently been proposed (see the entry on  chaos),  “nothing like this is actually needed” (Wolfram 2002: 752). By observing CA, we can understand how something with simple and definite micro-rules, like those governing our neurons, can produce a behavior free of obvious rules: 