Final answer:
Our only evidence of a material world, according to Berkeley, is through sensation, which is the perception of objects as ideas within the mind of God. This idealistic viewpoint asserts that material objects do not exist independently of divine perception, and thus the material world is essentially built on the divine ideas caused by God.
Step-by-step explanation:
According to Berkeley, our only evidence of a material world is sensation, which is the perceiving of objects. Berkeley argued that what we consider the physical, material world does not exist autonomously from the mind. Instead, material objects and their qualities are nothing but ideas, and all physical things in this world are essentially ideas of the divine.
He posited that these ideas are caused by God and exist within the mind of God. When God causes us to perceive an object, it is then that we sense the 'physicality' of that object. Without these divine ideas, there would be no sensation and thus no material world, as we would understand it, as all sensed objects are dependent on thought.
Berkeley's stance is a form of idealism that refutes the independent existence of material substances. This philosophical position is labeled dogmatic idealism which forms part of the broader study of ontology, the study of existence and reality.