australian citizens dont have many human rights (legally), among those existent including the right to vote (in fed elections) and freedom of religion. So, we have a right to vote, but that isnt a duty. UN conventions have the right to self- determinantion (the right for people to determine their own form of governent), but again, this is a right. So, in this respect, voting shouldnt be compulsory, however those reasonably of sound mind (adult, mentally able) and qualified (e.g. australian citizen) should be permitted to vote if they choose to do so.