text: This gives logic a mathematical foundation with equations, enables it to solve equations as well as check validity, and allows it to handle a wider class of problems by expanding propositions of any number of terms, not just two.Charles Darwin regarded Aristotle as the most important contributor to the subject of biology.In an 1882 letter he wrote that "Linnaeus and Cuvier have been my two gods, though in very different ways, but they were mere schoolboys to old Aristotle".Also, in later editions of the book "On the Origin of Species', Darwin traced evolutionary ideas as far back as Aristotle; the text he cites is a summary by Aristotle of the ideas of the earlier Greek philosopher Empedocles.Surviving works Corpus Aristotelicum The works of Aristotle that have survived from antiquity through medieval manuscript transmission are collected in the Corpus Aristotelicum.These texts, as opposed to Aristotle's lost works, are technical philosophical treatises from within Aristotle's school.Reference to them is made according to the organization of Immanuel Bekker's Royal Prussian Academy edition (Aristotelis Opera edidit Academia Regia Borussica, Berlin, 1831–1870), which in turn is based on ancient classifications of these works.Loss and preservation Aristotle wrote his works on papyrus scrolls, the common writing medium of that era.His writings are divisible into two groups: the "exoteric", intended for the public, and the "esoteric", for use within the Lyceum school.Aristotle's "lost" works stray considerably in characterization from the surviving Aristotelian corpus.Whereas the lost works appear to have been originally written with a view to subsequent publication, the surviving works mostly resemble lecture notes not intended for publication.Cicero's description of Aristotle's literary style as "a river of gold" must have applied to the published works, not the surviving notes.