Note 1684 — Chapter LVIII

Ibid., “Oportet ut medicina simplex quae experiatur sit pura et munda ab omni extranea qualitate, ne per illam extraneam qualitatem impediatur propria operatio medicinae, et per consequens cognitio experimentalis.” This is the same as Peter’s first condition. Also as the passage from Galen’s Medicinal Simples, II, 5, quoted in John’s Concordances, “Oportet quod res quae experitur sit pura et denudata ab omni qualitate accidentali....”