This objection states that the cosmological arguments commits a fallacy of composition.
What is a fallacy of composition and how does it relate to the cosmological argument?
Firstly, the word fallacy. A fallacy is a false idea, belief or notion. It literally means ‘a deception’, so in philosophy, a fallacy refers to a deceptive, false or misleading idea found within an argument. In philosophy, there are lots of fallacies that can be committed – these are the common mistakes found in arguments and they are always bad news for the strength of an argument.
One of these is the fallacy of composition. This is where the argument assumes, infers or claims that a characteristic of part of a thing is also a characteristic of the whole thing. For example, I might look at the front door of a house and see that it is white. If I then say that since part of the house (the door) is white, the whole house is white, I have committed a fallacy of composition. Notice, the whole house might be white, but I can’t claim that this is true based solely on the colour of the front door.
Another example might be if someone stands up at football games, they get a better view. But if everyone stood up, would everyone get a better view? Of course not. The reasoning here is fallacious as it commits a fallacy of composition.
How then, does this apply to the cosmological argument?
David Hume argued that the cosmological argument commits a fallacy of composition. The argument starts with an observation that some things are possibles, that is, some things are contingent. From this, the Thomist argument claims that the universe is contingent, and since contingent things cannot bring themselves into existence, there has to be a necessary being on which all contingent things depend of their existence. Have you noticed the fallacy of composition?
Clearly things around us are contingent, that is, parts of the universe are contingent. However, if we then argue that the whole universe is contingent on this basis, then it seems we commit a fallacy of composition.
Thinking that the whole house is white on the basis of a white front door would be a fallacy of composition, but clearly, we could take a step back, look at the whole house to see if is white or not. However, we can’t do this with the universe. We can’t take a step back and look at the whole universe to see if it is contingent. So we would have to assume that the whole universe is contingent on the basis that things in the universe are contingent, and this is a fallacy of composition.
All of this means that we cannot know that the universe is contingent and so there would be no need to have a necessary being to explain it.
Put another way, just because things in the universe have a cause does not mean that the universe has a cause.