We can say that the macro properties are emergent properties (non existent at the previous level of complexity, that of atoms) dependent also (apart the quantum laws) on the complex arrangements of the elements at the 'lower' structural level. In the case of many such emergent properties (such as wetness, solidity, colour) 'reduction' at the quantum theories is possible (if we add some extra assumptions needed to bridge the languages used at the macro level and that used by QM). It is conceivable that the process can be extended at even higher levels (for ex. that covered now by the 'higher level' sciences such as biology, economics etc), this at least in theory, for it is becoming very quckly virtually impossible to deduce the properties of very complex systems from QM (even using approximations). However no one can be sure that all emergent properties are truly reducible to the laws of QM, there are scientists (see for example Paul Davies in 'The fith miracle' or his article in the book 'The next fifty years') who believe that there are truly emergent laws at very high levels of complexity which cannot be reduced (notwithstanding that they are survenient on the quantum level and quantum laws they cannot be deduced from there). The most well known case is that of consciousness who might be such an irreducible property of matter appearing due to very high complexity at very high organizational levels. Why is it so? More generally, why are emergent properties-reducible or not-such as we observe them? Well the answer, fully compatible with the actually accepted notion of rationality, is that we have to just accept that this is a fundamental feature of nature, this is how nature work (letting the door open to something more fundamental, such as a Creator's will, this 'cluster' of hypotheses is by no means totally discredited; though of course it has no epistemological privilege currently).