It may seem that we have already answered this question. Hasn’t the argument in the previous Article already shown that man’s property of acting for an end is due to his rational nature? No, for that argument showed only that man’s manner of acting for an end – his dominion over his deeds – is due to his rational nature: He acts toward ends and knows what his ends are. Could it be that in some sense, creatures that lack reason will also act for an end? The tradition has held that they do – that all things in nature are directed to ends, even among the lower creatures that do not know what they are doing. St. Thomas seeks to find out whether this is true.