Prehension

One of the big questions that Whitehead deals with is change. How can something remain essentially itself yet continually change? The basic idea is that the entity always has a form that limits how it can change. The seed in this image can become a plant but not an animal. How it becomes that plant is determined by the opportunities it is given in the environment. It is wet or dry, sunny or shady, friendly or hostile? The seed changes based on two main properties, its own physical structure (its past or objective form) and the response it has to the future opportunities. Whitehead sees that only changing entities are really real so that the physical form an entity takes after it has changed is taken over (as this seedling is grown over by each new stage) by the actual new entity (called the occasion or event) that incorporates the old and adds what new opportunities are available. Whitehead calls this "prehension."