The passage of the three-fifths clause, allowing that three-fifths of all other persons (i.e. slaves) were to be taken into acocunt when determining congressional representation for each state in the new legislature, could give rise to the sense that there was no debate as to the morality of slavery in the United States. However, if one looks the character of the debate, then it becomes apparent that the three-fifths compromise was fundamentally about state interests, not the morality of slavery. Both the northern and southern states were concerned with the amount of power each state or group of states would hold in the new legislature. The inclusion of the three-fifths clause ensured that the interests of the souther and less populous states wouldn't be undermined by those of the northern or more populous states. the adoption of the three-fifths clause didn't explicitly endorse a racial hierarchy nor did it support militant proslavery ideology. Instead, it emphasized two of the more important functions of government: protect the rights of property ownership and ensure an equal distribution of power. Thus, it is easy to see how the debate over the three-fifths clause was one about state power and property, not the morality of the institution of slavery. There was little to gain for both the northern and southern delegations by engaging in a debate as to the morality of slavery.
However, there was at least one recorded private moral objection to the institution of slavery during the convention. On July 9th, John Dickinson of the delegation from Delaware, writting in his private notebook, recorded his thoughts about the ongoing three-fifths debate: "Acting before the World, What will be said of this new principle of founding a Right to govern Freemen on a pwer derived from Slaves,... [who are] themselves incapable of governing yet giving to others what they have not. The omitting [of] the WORD will be regarded as an Endevour to conceal a principle of which we are ashamed."