Sentence:  He says : `` Beside the Protestant philosophy of Progress , as <WSD>expressed</WSD> in radical or conservative millenarianism , should be placed the doctrine of the democratic faith which affirmed it to be the duty of the destiny of the United States to assist in the creation of a better world by keeping lighted the beacon of democracy '' . 
Meaning of the word marked with <WSD> tags:  serve as a means for expressing something