\section{A program for science}
%
%\newtheoremit{conjecture}[definition]{Conjecture}
%
In psychology one often is suspicious about information obtained through introspection. The
meditation experience, however, is obtained by introspection of a trained mind. In part I
it is argued that the truth of statements 
verified by meditative experience is as reliable as that
of mathematical theorems. Indeed, mathematics also is based on intuition in a trained mind.
It will be of definite value, nevertheless, 
if the reported phenomena can be verified by external
ex\-pe\-ri\-men\-tal science. Probably several other phenomena will be discovered along the way. 
How this should be done is totally unclear. It may keep us busy for the next century.

\subsection*{Value of the cover-up model}
%
This paper has given in $\S 2$ a description of a model for one aspect of the human mind, based
on  experience obtained during Buddhist meditation. The model explains how the mind is in an
impure state and that our behavior is in fact a symptomatic cover-up of this imperfection.
Also the model describes how this imperfection may be purified. No explanation has been given,
however, why the mind is impure and how the process of purification works. (In the monastery
the monks are not allowed to think about this; it distracts from the work to be done.
Back at home I do want to think about these matters.)

One may wonder what is the value of the model with its `cover-up' mechanism for suffering
and desire. An alternative common sense model could be that at a moment in which unpleasant
things happen  to us an {\em ad hoc\/} process of suffering is 
created and similarly for desire when we are in pleasant
circumstances. This common sense model has as drawback that there is no natural place in it for 
the possibility of purifying the mind. In this model a purified mind can be seen at best as one
in which the emotions of suffering and desire do not function anymore. A rather boring view
of buddhahood in which it is confused with indifference. 
Because it often is
in view of the common sense model that  perfection is interpreted,
many persons are repelled by it.
The cover-up model gives a
better meaning to the purification of the  mind
in which there is no indifference but {\em equanimity}. 
Also there is a clear place for mysticism in
this model. In the common sense model this state beyond fear and desire is difficult to
interpret.

To skeptics this argument may not be convincing, because it presupposes that there is something 
like purification of the mind. There is, however, a well-known fact in medical science that may 
help to appreciate the value of the cover-up model. People react differently to pain. That is, 
one person may feel just a little pain whereas another person feels much pain at the same outer
stimuli. In the cover-up model this can be explained by assuming that the fundamental process is 
of different degrees of strength in different persons. In the common sense 
model one has to assume 
that the ad hoc process of suffering has various degrees of strength in different persons. If it
is true that having a low pain threshold is uniform in the sense that a person is in the same 
degree more sensitive than others to various kinds of pain, including psychological forms of 
pain, then this is some evidence for the cover-up model. Indeed, the degree of strength of the
fundamental process, together with the cover-up mechanism implies some kind of uniformity.

The model of imperfection and its purification explains well an important incident
in the history of Chinese Buddhism. At the time that Hung Jen, the fifth patriarch 
of zen Buddhism in China, felt that he wanted to
appoint his successor, he asked his disciples to write 
a poem expressing their understanding
of the teachings. Then the head monk Shen Hsiu wrote the following poem.\medskip\\
\begin{tabular}{ll}
&{\em The body is like the bodhi\footnotemark tree,}\\
&{\em the mind is like a mirror bright.}\\
&{\em Constantly we should wipe them clean,}\\
&{\em Not allowing any dust to align.}\medskip
\end{tabular}\\
\footnotetext{The word `bodhi' means enlightenment; hence `bodhi tree' refers to the one
under which Buddha is said to have reached enlightenment.} 
Monks at the monastery were
impressed and expected that the head-monk would become the successor of the fifth patriarch.
There was, however, a novice named Hui Neng that could not read  or write. When he heard the
verse of the head monk he asked a friend to write down the  following poem.\medskip\\
\begin{tabular}{ll}
&{\em There is no body,}\\
&{\em there is no mind.}\\
&{\em Since fundamentally nothing exists}\\
&{\em where is the dust to align?}\medskip
\end{tabular}\\
It was Hui Neng who was chosen as sixth patriarch. How can we understand this? The head monk
was describing the state of mysticism in which one has to keep working to keep the volume of
feeling at level (see fig.3). Hui Neng described the state of nirvana (fig.12), 
in which no work needs to be done. 

\subsection*{Some conjectures}
%
Experience with the path of purification leads me to make several statements. Although I
fully  believe most of the statements, I will formulate them as conjectures. It will
be worthwhile to look for some experimental evidence for them.  In the process of doing this
more information probably will be obtained about the human mind.

The first conjecture is concerned with the correctness of the principal model 
given in this paper.

\begin{conjecture}
The cover-up model describes correctly the mechanism of suffering and desire.
\end{conjecture}

The next conjecture is about psycho-somatic phenomena. It almost sounds too good
to be true, because one explanation is given for a variety of syndromes.
Nevertheless, in the course of the path of purification very clear evidence has
been obtained.

\begin{conjecture}
The fundamental process may localize at certain places in the body and cause several 
psycho-somatic problems.
\begin{sub}
\item Torticollis may be caused by a localization of the process in the neck. 
(This means that the neck is forced in an unnatural position, e.g.\
with the head always towards the right.)
\item Ulcers may be caused by a localization of the process in the stomach.
\item Migraine may be caused by a localization  in some unusual part of the
brain.
\item Hyper-ventilation may be caused by a localization of the process 
in the center for control of breathing.
\item Eczema may be caused by the localization of the process in the skin.
\end{sub}
\end{conjecture}
% 
Some phenomenological evidence for this conjecture is the following.
Experiencing the nausea, it suddenly may happen that it disappears. At such a
moment the mind is completely free. Careful observation of the body, however,
shows that then the process is located somewhere else in the body. This
localization can be at various places. If the process is left at such a
location, then the effects mentioned in the conjecture can be observed (in a
mild  form).

The second conjecture is about psychological effects. These are claimed to be caused by special
ways of covering up the process.

\begin{conjecture}
\begin{sub}
\firstitem Phobias are caused by covering up the process using fear, a strong 
source of feeling that is preferable to the selflessness of the process. 
{\em This is the model of phobias of my father in Barendregt [1982], ch. 12.}
\item Depressions are an efficient way to cover-up the process. Again one has to pay for it
by being in an undesirable state.
\item Hypnosis can be explained as follows. 
During the induction of the hypnosis one has successfully made a link between 
behavior (the post-hypnotic order) and the cover-up of the process. An efficient 
way to avoid experiencing the process is to obey the post-hypnotic order.
\end{sub}
\end{conjecture}
%
Some evidence for this last conjecture concerning hypnosis was given in part I, $\S 3.6$.

These somatic and psychological effects are well-known but nevertheless not daily occurring to
most persons. A very common effect of the process is described in the following conjecture.

\begin{conjecture}
Ego, the way we see ourselves having important effects on the way we behave, is linked to
a cover-up of the process by the feeling it gives to us. Therefore we are attached to our way
of being. This link is even so strong, that one almost can identify the (first) process 
with ego. This also explains why the cessation of the first process corresponds to stopping
the belief in ego as a separate entity. 
\end{conjecture}

In Hofstadter [1979] a thesis is stated (on page 709)
that our feeling of self is related to `strange loops'.
A strange loop is something that is isomorphic to a part of itself. The image we obtain in a 
mirror, if another one is put opposite to it, ideally forms a strange loop.

\begin{conjecture}
The isomorphism in the strange loop that is involved in our self-consciousness is related to
mindfulness.
\end{conjecture}
%
Some evidence for this thesis is that in the meditation practice one has sometimes the
experience of an awareness of an awareness of an awareness of an ... , pointing at a strange
loop and its potential infinity. This is at the same time evidence for Hofstadters thesis. The 
role of mindfulness is evident from the role awareness plays in this observation.

Lucas and later Penrose [1989] have claimed that it follows from G\"odels incompleteness 
theorem that the human mind
is not a computer. I disagree with the reasons they give, agreeing for example with
Hofstadters refutation of Lucas' argument. Ne\-ver\-the\-less, I do agree with the thesis that
the human mind is essentially different from a (present day) computer (including neuro
computers). The reason comes from meditation practice in which one can experience that there is
something like nirvana that is awareness without perception or consciousness.

\begin{conjecture}
In the eventual theory of human consciousness nirvana will play a crucial role. It will be an 
important step forward if nirvana can be described in terms of physics.
\end{conjecture}

The process, its unbearableness and the possible liberation from it are so to speak axiomatic
properties of the model given in this paper.
The following conjectures are concerned with the background of this model.
They are presently more important than the previous one because there is more chance 
of verification at the present stage of science.

\begin{conjecture}
The human mind has more than one center of control (for our thoughts and emotions).
But only one of these is visible in our momentary consciousness. At
different moments we may be in different centers of control.
These centers are not synchronized.
The fundamental process is the friction, a neural storm, caused by this asynchronism.
The act of mindfulness makes a partial synchronization between the 
centers of control. Also walking
meditation described in part I, with its left-right symmetry, 
plays an important role in this synchronization.
The cessation of the process means a complete synchronization of some centers of control.
\end{conjecture}

Some well-known 
evidence for the fact that we have more than one consciousness process, more than one mind,
is the following. If we stay up late, then we become sleepy. If we stay up
long enough, it may happen that suddenly we
are not sleepy anymore. Although we react normally, we can feel in such a state that we are in
a `different' consciousness process. Relatively early in the meditation experience one 
repeatedly experiences transitions to other centers of consciousness. This happens during the
mystical state. During the transition one has to `cross' the fundamental process, which
at this time feels like an area of sleepiness.

The following is an important consequence.

\begin{corollary}
The well-known phenomena of the multiple personality syndrome are quite natural
aspects of the human mind. In `normal' people the various personalities are
similar. In `pathological' cases the various personalities are dissimilar.
\end{corollary}
%
Whether meditation may cure some forms of the multiple personality syndrome
I do not know.


A friend psychiatrist suggested  
the following chemical basis for the hi\-ding of the process.

\begin{conjecture}[M. Fraenkel]
`Feeling', that is used for the symptomatic hiding of the
process, is caused by endorphins produced by our body-mind system.
\end{conjecture}
%
As endorphins are similar to heroin, this hypothesis explains well why our attachments
are so stubborn. Or conversely, the model explains the well-known effects of heroin.


I hope that many people will work on this fascinating subject of the human mind. Perhaps
as a consequence meditation will become more widely known. Let it be for the well being of
all human beings.
