Latex 17th century, latex has been used as a term for the fluid substance in plants. It serves mainly as defense against herbivorous insects. Latex is not to be confused with plant sap; it is a separate substance, separately produced, and with separate functions. The word latex is also used to refer to natural latex rubber, particularly non-vulcanized rubber. Such is the case in products like latex gloves, latex condoms and latex clothing. Originally, the name given to latex by indigenous Equator tribes who cultivated the plant was “caoutchouc”, from the words “caa” (tear) and “ochu” (tree), because of the way
Mental substance Mental substance Mental substance is the idea held by dualists and idealists, that minds are made-up of non-physical substance. This substance is often referred to as consciousness. This is opposed to the materialists, who hold that what we normally think of as mental substance is ultimately physical matter (i.e., brains). Descartes, who was most famous for the assertion "I think therefore I am", has had a lot of influence on the mind–body problem. He describes his theory of mental substance (which he calls res cogitans distinguishing it from the "res extensa") in the "Second Meditation" (II.8) and in "Principia Philosophiae"