Language, Truth, and Logic by AJ Ayer

Mental ejaculations. That's what most of philosophy is if you follow Ayer. Metaphysics, theology, aesthetics, and much of ethics is cognitively meaningless. The whole book is pretty simple, it is a phenomenalist account of empiricism in which sense data is all that exists, but adds to traditional empiricist accounts the idea that a priori truths are not subject to empirical verification not because empiricism is limited, but that a-priori truths tell us nothing new. This is the crucial innovation of the logical positivists, that a statement like 2+2=4 doesn't need to be continually proved by experience or shows that there is non-empirical knowledge. Our logical constructions are just that, constructions of language related to the phenomenal world. 7+5=12 is true because 12 is defined as containing those numbers. This is course inspired by Wittgenstein's Tractatus.

All meaningful statements, from the radical empiricist view, are either analytic or synthetic. Analytic statements are tautologies, definitions of particular experiences which are either true or false by non-contradiction based on how they are defined. Synthetic truths are empirical statements about differently defined observations which aren't absolutely true or false but only probabilistically. When we say a causes b, we are really saying A and B occur close together enough that we assume the appearance of A brings to mind the appearance of B. All this an updated version of David Hume's distinction between relations of ideas and matters of fact.

Ayer invokes the old Epicurean argument against those who say that the senses are flawed, limited, or only give us a picture of reality. The senses don't lie, they are passive. It is our expectations based on past experience about what will occur in the future that deceives us. And epistemologically, from what standard do we criticize our senses? How do we know there is a real world beyond our senses if we cannot trust the senses? In reality what we view as reality is a selective construction of certain experiences. The "underlying world" is just experience itself as it enters our perception before we consciously categorize it.

Of all the traditional philosophy Ayer describes as meaningless, only ethics survives in a very limited way. He gives an emotive account of ethics, which does not add truth or falsity to a statement but expresses either our approval or disapproval or a command for someone to do something. All else in ethical discussion is either a clarification of language or metaphysical and therefore meaningless.

The conventional wisdom if there is such a thing among philosophers is that logical positivism especially as presented by Ayer has been refuted. It is said that the verification principle, which gives meaning only to what can be based on sense experience, cannot itself be verified. Or that there isn't really a distinction between analytic and synthetic. Just reading it for myself, it sounds plausible. It is just so satisfying to believe all truths are either definitions or observations. So simple, maybe that's the problem.

For philosophy students, I think that the arguments presented here could be a way to get into analytic philosophy, or at least generate some interest. That's what it did for me, in a very accessible way.