 Perhaps we are now in the position to understand how Aristotle argues that there are four kinds of causes and at the same time says that proper knowledge is knowledge of the cause or knowledge of the why (APost. 71 b 10–12, 94 a 20; Phys. 194 b 17–20; Metaph. 981 a 28–30). Admittedly, at least at first sight, this is a bit confusing. Confusion dissolves when we realize that Aristotle recognizes the explanatory primacy of the final/formal cause over the efficient and material cause. Of course this does not mean that the other causes can be eliminated. Quite the contrary: Aristotle is adamant that, for a full range of cases, all four causes must be given in order to give an explanation. More explicitly, for a full range of cases, an explanation which fails to invoke all four causes is no explanation at all. At the same time, however, the final/formal cause is the primary cause and knowledge of this cause amounts to knowledge of the why.