Lignum vitae wood can also be used to brew a tea. Other names for lignum vitae include palo santo (Spanish for "holy wood") Aura palo santo and "bastard greenheart" (not to be confused with true greenheart "Chlorocardium rodiei", a popular wood in shipbuilding, cabinetry, and woodturning but a completely different timber). Lignum vitae is also one of the numerous hard, dense woods loosely referred to as "ironwood". Lignum vitae is hard and durable, and is also the densest wood traded (density: 1.23 g/cm); it will easily sink in water. On the Janka Scale of Hardness, which measures hardness of woods, lignum vitae
Mental substance (2.002). He used a more precise definition of the word "substance" than is currently popular: that a substance is something which can exist without the existence of any other substance. For many philosophers, this word or the phrase "mental substance" has a special meaning. Gottfried Leibniz, belonging to the generation immediately after Descartes, held the position that the mental world was built up by monads, mental objects that are not part of the physical world (see "Monadology"). 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