For several millennia, people reflecting on the nature of reality understood it to be a certain way. They saw essentially two things: First, reality exists, i.e. there was something “out there”. And second, there were minds to perceive that reality. But something happened during the development of our understanding of what exists (i.e. ontology). A split emerged between two camps. On the one hand there were realists who believed that the world existed out there, i.e., independent of our thoughts. On the other there were skeptics who began to doubt our ability to grasp the world out there. Whereas Aristotle argued that reality is divided up between various substances, Kant argued that reality is divided up between the actual world (the noumenal) and the world as it appears to us (the phenomenal). Others would eventually build from Kant’s characterization essentially arguing that we should doubt that material things exist at all.
This disagreement over ontology has not waned, as even today folks go back and forth over the nature of the external world. Christians are not immune from this debate either. George Berkeley, Bishop of Cloyne, was a Scottish philosopher convinced that material objects did not exist; rather, the only things that exist are minds and ideas. This particular view is known as idealism. While idealism was a rather novel philosophical approach for the 18th century, some current Christian thinkers (some I even greatly admire) are beginning to advocate for this belief once again. They self-identify as theistic idealists. Their belief: The only things that exist are minds (ours and God’s) and ideas.
Two typical reasons that theistic idealists appeal to their view of reality are: First, they appeal to the idealist argument itself, that is, George Berkeley’s arguments for an idealist conception of reality; second, they appeal to how science, specifically quantum physics, supports the idealist worldview. This post will focus on why I believe both of these appeals are unjustified.
Part 1: The Argument
George Berkeley wrote two important works concerned with refuting the notion that material objects exist: Treatise concerning the Principles of Human Knowledge (1710) and Three Dialogues between Hylas and Philonous (1713). In both of these writings he laid out arguments surrounding a few central propositions:
- An object is simply a collection of ideas.
- For something to exist, it must be perceived by a mind. If it is not perceived, it does not exist.
- Because we only perceive ideas, nothing else exists except ideas (and minds).
#1 An object is simply a collection of ideas:
At the outset it should be noted that this first proposition provides the foundation for the other two. Thus, if I can show that this first proposition does not go through, then the other two won’t either. Berkeley writes,
“It is evident to any one who takes a survey of the objects of human knowledge, that they are either ideas actually imprinted on the senses; or else such as are perceived by attending to the passions and operations of the mind; or lastly, ideas formed by help of memory and imagination…”
Berkeley goes on to list objects that we perceive, like a stone, a tree, a table, etc. How do we perceive these objects, Berkeley asks? Only by interaction with our minds. But, as Berkeley shows in the quote, our interactions with objects are only ideas imprinted on the senses. In other words:
- We perceive objects by sense
- Our perceptions are only ideas
- (Therefore) Objects are ideas
Here’s where this argument falls apart for me. Let’s concede Premise 2 for argument’s sake. It does not follow that because our perceptions are only ideas that the objects we perceive are only ideas. This conclusion is actually an assertion that requires further argumentation; except Berkeley does not provide this, he simply asserts it. In point of fact, it seems that Berkeley has made a mistake by equivocating between the act of perception and the objects being perceived. Think of it this way: When we perceive a pine tree there are two distinct things comprising the event: #1 there is the thing that we are aware of (e.g. the smell or sight of a pine tree); and #2 the actual act of apprehending the pine tree through our sense of smell or sight. While it can be argued that #2 is a mental event, #1 is not. And the mistake that Berkeley makes is to equivocate #1 and #2 as if they are the same when they are not.
#2 For something to exist, it must be perceived by a mind. If it is not perceived, it does not exist:
“That neither our thoughts, nor passions, nor ideas formed by the imagination, exist without the mind, is what everybody will allow. And it seems no less evident that the various sensations or ideas imprinted on the sense, however blended or combined together (that is, whatever objects they compose), cannot exist otherwise than in a mind perceiving them.”
Again, this proposition only works if the previous one does. The transition goes like this: Once it is established that objects are only ideas, it follows that objects cannot exist unless minds exist to perceive them. In other words:
- An object is an idea
- Ideas only exist in minds
- (Therefore) An object can only exist in a mind
For example, a pine tree is an idea but ideas only exist in minds; therefore, the pine tree can only exist in a mind. This argument certainly seems sound if we accept that the pine tree is an idea. However, as I previously showed, Berkeley has no good argument to support the claim that, because perceptions of pine trees are only ideas, then pine trees themselves must only be ideas. So we cannot move on to Berkeley’s second proposition until he establishes a solid argument for Premise #1. But he never provides an argument, he only asserts as such. So there is no good reason to accept this argument.
#3 Because we only perceive ideas, nothing else exists except ideas (and minds):
This particular notion trades on our accepting the thesis that our perceptions are only ideas. Earlier I conceded this claim for argument’s sake but we don’t have to. The path from Premise #1 of the first argument (We perceive objects by sense) to Premise #2 (Our perceptions are only ideas) is not very clear. To go back to the previous example, it could be the case that our senses are apprehending real pine trees directly. It could also be the case that we perceive a mental representation of a pine tree by interacting with a real pine tree. In other words, there are other options besides suggesting that the only thing we perceive are ideas of pine trees. Since Berkeley has not given a good reason why we only perceive ideas, then the proposition that nothing else exists except ideas does not go through.
The question of metaphysics, particularly ontology, is not an easy endeavor, and I’m sympathetic to those who hold to Berkeley’s view. But it seems to me that theistic idealists have forgotten a simple principle: Beyond the arguments for this or that view, intuition (what some refer to as common sense) needs to be considered as well. It is hardly controversial to point out that our common sense intuitions comport with the view that the external world exists independent of our minds. Even antirealists admit this. But theistic idealists don’t consider that common sense is, itself, a rational epistemic criterion just as weighty as a philosophical argument. Sure, intuitions can be wrong, but so can arguments. All of Berkeley’s arguments deny our common sense experience of the world God made. Thus, to hold a view that forces theistic idealists to deny common sense is to lose sight of reality and get lost in ideas.
 George Berkeley, A Treatise Concerning the Principles of Human Knowledge (Mineola, NY: Dover Publication, 2003) 29.
 Ibid, 30.
 To be is to be perceived.
 Ibid, 31.