George Berkley
(1685 – 1753)
Irish philosopher, the second of the “Holy Trinity” of British empiricism. Berkeley followed Locke, but was against rationalism and classical empiricism. He proposed a wholly different theory – which he himself called immaterialism (later called subjective idealism by others). He denies the existence of material substances and says that all material objects (and reality) are just ideas perceived by the mind and cannot exist without being perceived.
His most important work is A Treatise Concerning the Principles of Human Knowledge (1710), where Berkeley argues against John Locke about the nature of human perception. The book was poorly received and Berkeley rewrote it as the Three Dialogues (1713), where his philosophy is written out as an imaginary dialogue between Philonus (in Greek: “lover of mind”), who represents Berkeley’s views, and Hylas (in Greek: “matter”) who embodies his opponents, particularly Locke.
In his work, Berkeley argues against Locke’s distinction between primary and secondary qualities (see Locke on primary and secondary qualities).
– Berkeley believed that we cannot distinguish primary qualities (e.g. shape – which according toLocke exist independently of the mind) from secondary qualities (e.g. colour – which exist in themind of the observer).
– According to Berkeley, our only access to objects is through secondary qualities, and we canonly know the size, shape, location or dimensionality of an object by feeling or sensing it – like how we recognise an object by its colour – the colour red can be perceived in apples, strawberries and tomatoes, but we wouldn’t know how these look without the colour. We would also not know what colour red looks like, if there was no red paint, or any object that is perceivably red.
– From this, we see that colours cannot exist on their own and that they represent perceived objects. Berkely’s conclusion is that descriptions of primary qualities are actually just interpretations of secondary qualities (ie. different ways of talking about colours, sounds, tastes, tactile sensations), and that both, primary and secondary qualities are dependent on the mind.To explain the translation of secondary qualities into primary qualities, Berkeley draws a distinction between direct and indirect perception.
– direct (or immediate) perception: passive reception of basic sense data (Locke’s secondaryqualities and simple ideas)
– indirect (mediated) perception: interpretation of sense data (above) – through language
* For example: A child who doesn’t know how to read, sees letters on a book page as just black scribbles (direct perception). Through the process of learning, the child eventually learns to see the scribbles as words that have a meaning (indirect perception). Once he learns to read, it is basically impossible to see the page as just scribbles.
—> this is analogous to what Berkeley says about our how we perceive and construct knowledge of the external world: his subjective idealism holds that each one of us lives in their own world that is composed of sense data. Just like the child, we are taught language and how to read sense data, and learn how to organise them into things and ideas in our mind. For Berkeley, the above two categories (sense data and language) account for all possible human knowledge
– except the knowledge of God. God’s existence can be deduced from the regularity and predictability of sense data.
—> If the physical world exists to be perceived, why do things still exists when nobody is perceiving them (when I leave the room, the room doesn’t just disappear) – because God is perceiving it when we are not. In this way, God guarantees the existence and laws of nature.