- Siliceous rocks are sedimentary rocks that have silica (SiO2) as the principal constituent. The most common siliceous rock is chert; other types include diatomite. They commonly form from silica-secreting organisms such as radiolarians, diatoms, or some types of sponges.
- Proslogion (Wikipedia)
The Proslogion (Latin: Proslogium, lit. ‘Discourse’) is a prayer (or meditation), written by the medieval cleric Saint Anselm of Canterbury in 1077–1078, serving to reflect on the attributes of God in order to explain how God can possess seemingly contradictory qualities. This meditation is considered to be the first-known philosophical formulation that sets out the ontological argument for the existence of God.