What beliefs about the sentience of matter does Usher express to the narator?

From the text:

The conditions of the sentience had been here, he imagined, fulfilled in the method of collocation of these stones --in the order of their arrangement, as well as in that of the many fungi which overspread them, and of the decayed trees which stood around --above all, in the long undisturbed endurance of this arrangement, and in its reduplication in the still waters of the tarn. Its evidence --the evidence of the sentience --was to be seen, he said, (and I here started as he spoke,) in the gradual yet certain condensation of an atmosphere of their own about the waters and the walls. The result was discoverable, he added, in that silent, yet importunate and terrible influence which for centuries had moulded the destinies of his family, and which made him what I now saw him --what he was. Such opinions need no comment, and I will make none.