This shows as human involvement is design. Absolute necessity reigns over the heavens. Avempace views necessity into three kinds: absolute, design, and material. Avempace demonstrates the moon eclipses using absolute necessity over time. Based on the relations of the moon eclipses, Avempace indicates “possibility shares necessity”. He defines the body as an artificial collection of matter, which acts as an instrument for the soul to work through. In doing so, he establishes the soul as an autonomous subject. Avempace believes that the human soul has three stages. It starts in the plant stage, then to the animal stage, and finally to human stage. Each stage has an important attribute that the soul grows from. The plant life is where the soul is provided with nourishment and growth. In the animal stage, the soul is introduced to sensations. When the soul moves to the human state, the soul gains common sense, imagination, and memory. Additionally, Avempace writes that the soul is geometrically formless. Because its form is beyond our understanding of geometric shapes, he states, it exists on a plane higher than that which we perceive with our bodies. Avempace is said to have been influenced by Platonic and Aristotelian views on the subject. He credits Plato with the theory of the soul as a substance: