Today we saw that Berkeley sets himself the task of explaining everything making reference only to minds and ideas. We began with his account of bodies.
The task for Berkeley is to give an account of bodies using just minds and ideas. He thinks he can accomplish this by explaining bodies as collections of ideas. So what makes up a body like a chair is a collection of tiny ideas, what he sometimes calls ‘minima’ – the smallest perceivable ideas.
Like Locke, Berkeley thinks we understand bodies by forming collections of our own ideas. Now when it comes to sensing bodies, the ideas of sense are actually in both collections. They are in the collections that we form, and in the collections that actually make up bodies. Berkeley thinks this makes him a realist about perception.
Since minima play the role of atoms for Berkeley, he thinks he can avoid John Locke’s puzzle of the man with ‘microscopical eyes’. Locke worries that the man with microscopical eyes sees the truth while we cannot see truth because we cannot see atoms. But on Berkeley’s view, a single act of perception reveals idea-atoms (=minima) as well as bodies!
We then spoke about how Berkeley handles science and mathematics. Scientifically, Berkeley is an instrumentalist. He thinks science is a tool that is very useful, but the truth is to be found at the level of collections of ideas, rather than in scientific theories. Berkeley thinks that mathematics is a ‘creature of the mind’, a fiction, because math depends on assigning numbers to things, and there are many ways to number things (though some may be conventional).