"But I deny that the Constitution recognizes property in man"

William H. Seward's quote is a declaration of his opposition to the idea of slavery. He is rejecting that the Constitution of the United States acknowledges the right of someone to own another person as home. Seward is arguing that the Constitution does not approve anyone the right to own another individual as property, which the concept of slavery is not supported by the Constitution. He is also suggesting that the idea of slavery is ethically wrong and must not be tolerated. Seward's quote is an effective statement of his opposition to slavery and his belief that the Constitution does not recognize the right of one person to own another. It is a suggestion that the Constitution was composed to secure the rights of all people, despite race or social status, which slavery is an affront to those rights.