The word contemplation is derived from the Latin word contemplatio. Its root is also that of the Latin word templum, a piece of ground consecrated for the taking of auspices, or a building for worship, derived either from Proto-Indo-European base *tem- "to cut", and so a "place reserved or cut out", or from the Proto-Indo-European base *temp- "to stretch", and thus referring to a cleared space in front of an altar. The Latin word contemplatio was used to translate the Greek word θεωρία (theōría).
Contemplation was an important part of the philosophy of Plato; Plato thought that through contemplation the soul may ascend to knowledge of the Form of the Good or other divine Forms. Plotinus as a (neo)Platonic philosopher also expressed contemplation as the most critical of components for one to reach henosis. To Plotinus the highest contemplation was to experience the vision of God, the Monad or the One. Plotinus describes this experience in his works the Enneads. According to his student Porphyry, Plotinus stated that he had this experience of God four times. Plotinus wrote about his experience in Enneads 6.9.xx....
In Islamic tradition, it is said that Muhammad would go into the desert, climb a mountain known as Mount Hira, and seclude himself from the world. While on the mountain, he would contemplate life and its meaning.
In Eastern Christianity, contemplation (theoria) literally means to see God or to have the Vision of God. The state of beholding God, or union with God, is known as theoria. The process of Theosis which leads to that state of union with God known as theoria is practiced in the ascetic tradition of Hesychasm. Hesychasm is to reconcile the heart and the mind into one thing (see nous).
Contemplation in Eastern Orthodoxy is expressed in degrees as those covered in St John Climacus' Ladder of Divine Ascent. The process of changing from the old man of sin into the newborn child of God and into our true nature as good and divine is called Theosis.