I am going to give an improved formulation of some of the concepts explored in the previous post. First I present the following hypothesis:

**The Anoological Hypothesis.** It is impossible to arrive at reasoned consensus regarding the truth-value of any proposition about non-physical non-mathematical entities. In particular, it is impossible to prove any non-tautological proposition about non-physical non-mathematical entities.

“Anoological” is composed of the Greek words “nous” (mind or spirit) and “logos” (reason). Put simply, therefore, the anoological hypothesis is the hypothesis that we do not have rational knowledge of anything mental or spiritual. Put more precisely, we only have well-defined and widely agreed upon propositions about physical and mathematical entities, and we have no well-defined or widely agreed upon propositions about non-physical non-mathematical entities. Let us further explore the meaning of this hypothesis and the reasons for believing it.

Firstly, what is meant by “non-physical non-mathematical entity?” It is any entity that is not describable by the physical sciences or by mathematics. Such entities include God, souls, angels, demons, heaven, hell, Cartesian egos, astral planes, brahman, Platonic forms, etc. They also include thoughts, feelings, sensations, intentions, consciousness, etc., if these entities are not describable by the physical sciences.

We will divide the entities just mentioned into two further roughly defined categories, for convenience. “Psychological entities” are those entities which are features of the human mind, such as thoughts, feelings, sensations, intentions, and consciousness. “Spiritual entities” are God, souls, angels, etc. Psychological entities may or may not be non-physical non-mathematical entities. Spiritual entities definitely are. These categories are not intended to be precisely defined, or necessarily exhaustive of the category of non-physical non-mathematical entities.

The three categories “physical entities,” “mathematical entities,” and “non-physical non-mathematical entities” are intended to be exhaustive of all entities that are discussed by human beings. The inclusion of mathematical entities as a category is necessitated by the clear fact that mathematical entities are not physical entities, and nonetheless are the objects of our most firmly established knowledge. Here we must leave aside the debates about whether or not mathematical entities exist, and what they are if they do exist.

What is meant in the anoological hypothesis by “reasoned consensus?” Firstly, by “consensus” I mean the kind of consensus that mathematical and scientific propositions frequently obtain, where almost all people with knowledge on the subject agree upon a single truth-value for the proposition in question. Consensus is a measure of the level of agreement in informed peoples’ beliefs.

That non-tautological propositions about non-physical non-mathematical entities rarely have such consensus is readily apparent. Certain propositions about psychological entities have consensus, such as “pain hurts” and “pleasure feels good.” It is not clear, however, that any of these consensus-bearing propositions are non-tautological.

It is clear at any rate that there is no non-tautological proposition about any spiritual entity about which there is consensus. According to physicalists, spiritual entities do not exist, and therefore all non-tautological propositions except for “x does not exist” are false of spiritual entities. This proposition does not have consensus, because many people believe that spiritual entities do exist. Physicalists and believers in spiritual entities together assure that there is no non-tautological proposition about spiritual entities which has consensus, because physicalists deny all of the propositions which believers in spiritual entities affirm, and vice versa.

There have been, and are, groups of people in which non-tautological propositions about non-physical non-mathematical entities had or have consensus. The present entire world population is not such a group of people, but we can cite examples of other such groups. In Medieval Europe it was the consensus that heaven and hell existed. In much of India it is the consensus that people live through a series of incarnations. Among physicalists it is the consensus that spiritual entities do not exist.

When examining groups other than the present entire world population, it is sometimes the case that there is consensus about propositions about non-physical non-mathematical entities. However, in none of these cases (except possibly the case of physicalism) is this “reasoned consensus.”

“Reasoned consensus” means, consensus due to the fact that the propositions upon which there is consensus have been proven. “Proof” means the kind of justification provided for mathematical theorems or scientific hypotheses. It does not necessarily mean mathematical proof; there is the possibility of admitting much that is informal and uncertain in the kind of proof under discussion. It is conceivable that we could stretch the notion of “proof” to include some justifications for believing in physicalism. Though I myself do not believe that this is the case, I do think it is possible to argue it and so I do not assert positively that consensus about physicalism is never reasoned consensus. *At least all consensus besides physicalism* that has existed in human history regarding propositions about non-physical non-mathematical entities has not been reasoned consensus.

It is difficult to say precisely what proof consists of. What modes of reasoning are admissible? What types of evidence are admissible? What premises are admissible? Such problems are complex. One useful measure (but not a final definition) of proof is its ability to produce consensus. This would appear to create a circle in definition between “reasoned consensus” and “proof,” but it does not. Consensus can be produced through means other than proof, such as charisma, duress, or brainwashing. “Reasoned consensus” excludes all means of producing consensus other than proof.

That is all for the meaning of the anoological hypothesis. Let us now consider the grounds for believing it. These are chiefly empirical in the informal sense. Put simply, a great many propositions about physical and mathematical entities have been proven. No proposition about a non-physical non-mathematical entity has ever been proven. Even such valiant attempts as Descartes’ ontological argument have failed to produce consensus. That this has consistently been the case after many, many attempts to prove such propositions, is strong evidence for the proposition that it cannot be done. This proposition is the anoological hypothesis.

The anoological hypothesis, if true, has large implications. Specifically, it implies that all ontologies must be consistent with exactly one of two hypotheses:

**Physicalism.** Non-physical non-mathematical entities do not exist.

**Anoological non-physicalism.** Non-physical non-mathematical entities exist, and it is impossible to prove that they exist.

Physicalism is the usual choice in philosophy today. Anoological non-physicalism is a little-considered alternative, and also the only conceivable alternative to physicalism if the anoological hypothesis is true.

Furthermore, if the anoological hypothesis is true, *it is impossible to prove either physicalism or anoological non-physicalism.* This is so because physicalism and anoological non-physicalism are both propositions about non-physical non-mathematical entities, and under the anoological hypothesis such propositions cannot be proven. If the anoological hypothesis is true, then we are stuck with these two ontological alternatives, and no means to establish one over the other.