In addition to his works on ethics, which address the individual, Aristotle addressed the city in his work titled "Politics". Aristotle considered the city to be a natural community. Moreover, he considered the city to be prior in importance to the family which in turn is prior to the individual, "for the whole must of necessity be prior to the part". He famously stated that "man is by nature a political animal" and argued that humanity's defining factor among others in the animal kingdom is its rationality. Aristotle conceived of politics as being like an organism rather than like a machine, and as a collection of parts none of which can exist without the others. Aristotle's conception of the city is organic, and he is considered one of the first to conceive of the city in this manner.