A young physician was sent by the cardinal's party into the heterodox camp as a spy.

Having heard one lecture of Prof.See, he returned with information that seemed to promise easy victory to the besieging party: he brought a terrible statement--one that seemed enough to overwhelm See, Vulpian, Duruy, and the whole hated system of public instruction in France--the statement that See had denied the existence of the human soul.
Cardinal Bonnechose seized the tremendous weapon at once.

Rising in his place in the Senate, he launched a most eloquent invective against the Minister of State who could protect such a fortress of impiety as the College of Medicine; and, as a climax, he asserted, on the evidence of his spy fresh from Prof.See's lecture-room, that the professor had declared, in his lecture of the day before, that so long as he had the honour to hold his professorship he would combat the false idea of the existence of the soul.

The weapon seemed resistless and the wound fatal, but M.Duruy rose and asked to be heard.
His statement was simply that he held in his hand documentary proofs that Prof.See never made such a declaration.

He held the notes used by Prof.See in his lecture.