Certain general doctrines, the spirit of which runs through all the scientific works of Mr. Agassiz, are distinctly laid down in the first section of this chapter. It is headed with the statement, "The leading features of a natural zoological system are all founded in nature." The systems named from the great leaders of science are but translations of the Creator's thoughts into human language. "If it can be proved that man has not invented, but only traced this systematic arrangement in nature,--that these relations and proportions which exist throughout the animal and vegetable world have an intellectual, an ideal connection in the mind of the Creator,-- that this plan of creation, which so commends itself to our highest wisdom, has not grown out of the necessary action of physical laws, but was the free conception of the Almighty Intellect, matured in his thought, before it was manifested in tangible, external forms,-- if, in short, we can prove premeditation prior to the act of creation, we have done, once and forever, with the desolate theory which refers us to the laws of matter as accounting for all the wonders of the universe, and leaves us with no God but the monotonous, unvarying action of physical forces, binding all things to their inevitable destiny." One more extract must be given from this section, for it is the key to the general argument which follows. "I disclaim every intention of introducing in this work any evidence irrelevant to my subject, or of supporting any conclusions not immediately flowing from it; but I cannot overlook nor disregard here the close connection there is between the facts ascertained by scientific investigations, and the discussions now carried on respecting the origin of organized beings. And though I know those who hold it to be very unscientific to believe that thinking is not something inherent in matter, and that there is an essential difference between inorganic and living and thinking beings, I shall not be prevented by any such pretensions of a false philosophy from expressing my conviction, that, as long as it cannot be shown that matter or physical forces do actually reason, I shall consider any manifestation of thought as evidence of the existence of a thinking being as the author of such thought, and shall look upon an intelligent and intelligible connection between the facts of nature as direct proof of the existence of a thinking God, as certainly as man exhibits the power of thinking when he recognizes their natural relations."