Perceived and the Perceiver
The fundamental thematic assumption in the philosophy which is set out by Berkeley in this treatise concerns the nature of existence. The essentialist definition is thus: for something to exist it must either be that which is perceived or the entity which is perceiving it. For instance, a rock does not merely exist because it is said to exist. It can be said to actually exist as matter rather than mere idea only if it can be perceived someone. This is the irrefutable operable laws of existence that applies to all matter.
The Properties of Matter Do Not Exist
The properties of all matter do not exist in reality, but only through perception. A rock is a rock is a rock. Whether the rock is large or small, warm or cold, heavy or light are aspects which do not exist in reality, but only as aspects perceived by the observer. That these properties do not actually exist can be proven because they change according to perspective. The very same rock, for instance, will be perceived as large and heavy by a child but small and light by a huge adult. Likewise, properties like heat, color, texture vary depending on the relative position the perceiver brings to it. The only thing that exists in reality is the rock since is perceived to exist by all.
The Existence of God
The primary message forwarded in Berkeley’s thesis exists within the chasm of this definition of existence. If, as Berkeley argues, something can only exist if it the perceived or the perceiver, how does one explain the existence of obviously concrete things which clearly exist—or have existed—without ever being seen? According to the premise, would it not then be truthful to say until the first explorers reached it, the South Pole didn’t exist since it could not itself perceived, but only perceived which it wasn’t until it was? Did the South Pole not exist December 14, 1911 when Roald Amundsen and the member of his team became first recorded human beings ever to reach it?
The motivation behind Berkeley’s composing this treatise answers that question with an affirmative no. That which has not yet been perceived by man (or beast since their perceptual abilities also count) has been perceived by God. Thus, the treatise lays out an argument just for the nature of existence, but as proof of the existence of God. Without God, that which has never been perceived by man or beast could, by definition, not actually exist.
