Friday, April 4, 2014

The Creative Imagination -- by Michael Polanyi (PART 2)

In this second part of the essay Polanyi poses a question central to understanding the progression of scientific endeavor (see Part 1). On which grounds can we change the standards of coherence we use to judge our speculations/theorizing as real? “We are faced with the existentialist dilemma: how values of our own choosing can have authority over us who decreed them." The answer he suggests involves first a deliberate intent to go beyond what we know; this intent is part of what he calls imagination. This in turn may spark a spontaneous movement of intuition, which seeks a deeper coherence. The two work together to find and integrate clues leading to a more profound level of understanding. This occurs largely below awareness and encodes new standards of coherence that only become explicit afterwards. 

In the next post, we will present some of our personal reactions to Polanyi's exhilarating essay.

We begin to see how the scientist’s vision is formed. The imagination sallies forward, and intuition integrates what the imagination has lit upon. But a fundamental complication comes into sight here. I have acknowledged that the final sanction of discovery lies in the sight of a coherence which our intuition detects and accepts as real; but history suggests that there are no universal standards for assessing such coherence.

Copernicus criticized the Ptolemaic system for its incoherence in assuming other than steady circular planetary paths, and fought for the recognition of the heliocentric system as real because of its superior consistency. But his follower, Kepler, abandoned the postulate  of  circular  paths,  as causing  meaningless  complications  in the  Copernican  system,  and  boasted  that  by  doing  so  he  had cleansed  an Augean  stable  (Koestler,  1959, p. 334). Kepler based his first two laws on his vision  that geometrical  coherence  is the product  of  some mechanical interaction  (Koestler,  1959, p. 316), but this conception of reality underwent another radical transformation when Galileo, Descartes, and Newton  found ultimate reality in the smallest particles of matter obeying the mathematical laws of mechanics. (....)

It becomes necessary to ask, therefore, by what standards we can change the very standards of coherence on which our convictions rest. On what grounds can we change our grounds? We are faced with the existentialist dilemma: how values of our own choosing can have authority over us who decreed them.

We must look once more, then, at the mechanism by which imagination and intuition carry out their joint task.  We lift our arm and find that our imagination has issued a command which has evoked its implementation. But the moment feasibility is obstructed, a gap opens up between our faculties and the end at which we are aiming, and our imagination fixes on this gap and evokes attempts to reduce it. Such a quest can go on for years; it will be persistent, deliberative, and transitive; yet its whole purpose is directed at ourselves; it attempts to make us produce ideas. We say then that we are racking our brain or ransacking our brain; that we are cudgeling or cracking it, or beating our brain in trying to get it to work.

And the action induced in us by this ransacking is felt as something that is happening to us.  We say that we tumble to an idea; or that an idea crosses our mind; or that it comes into our head; or that it strikes us or dawns on us, or that it just presents itself to us. We are actually surprised and exclaim: Aha! when we suddenly do produce an idea. Ideas may indeed come to us unbidden, hours or even days after we have ceased to rack our brains.

Discovery is made therefore in two moves: one deliberate, the other spontaneous, the spontaneous move being evoked in ourselves by the action of our deliberate effort. The deliberate thrust is a focal act of the imagination, while the spontaneous response to it, which brings discovery, belongs to the same class as the spontaneous coordination of visual clues in response to our looking at something. This spontaneous act of discovery deserves to be recognized as creative intuition.

But where does this leave the creative imagination? It is there; it is not displaced by intuition but imbued with it. (....)

The imaginative effort can evoke its own implementation only because it follows intuitive intimations of its own feasibility (....)

The honors of creativity are due then in one part to the imagination, which imposes on intuition a feasible task, and, in the other part, to intuition, which rises to this task and reveals the discovery that the quest was due to bring forth. Intuition informs the imagination which, in its turn, releases the powers  of  intuition. (....)

When the quest has ended, imagination and intuition do not vanish from the scene. Our intuition recognizes our final result to be valid, and our imagination points to  the  inexhaustible  future manifestations of it. We return to the quiescent state of mind from which the inquiry started, but return to it with a new vision of coherence and reality. Herein lies the final acceptance of this vision; any new standards of coherence implied in it have become our own standards; we are committed to them. (....)

…[S]cientific discoveries are made in search of a reality--of a reality that is there, whether we know it or not. The search is of our own making, but the reality is not. We send out our imagination deliberately to ransack promising avenues, but the promise of these paths is already there to guide us; we sense it by our spontaneous intuitive powers. We induce the work of intuition but do not control its operations.

And since our intuition works on a subsidiary level, neither the clues which it uses nor the principles by which it integrates them are fully known. It is difficult to tell what were the clues which convinced Copernicus that his system was real. We have seen that his vision was fraught with implications so far beyond his own ken that, had they been shown to him, he would have rejected them. (....)

The solution of our problem is approaching here. (....) The deliberate aim of scientific inquiry is to solve a problem, but our intuition may respond to our efforts with a solution entailing new standards of coherence, new values. In affirming the solution we tacitly obey these new values and thus recognize their authority over ourselves, over us who tacitly conceived them.

This is indeed how new values are introduced, whether in science, or in the arts, or in human relations. They enter subsidiarily, embodied in creative action. Only after this can they be spelled out and professed in abstract terms, and this makes them appear to have been deliberately chosen, which is absurd. The actual grounds of a value, and its very meaning, will ever lie hidden in the commitment which originally bore witness to that value.

(….) The content of any empirical statement is three times indeterminate. It relies on clues which are largely unspecifiable, integrates them by principles which are undefinable, and speaks of a reality which is inexhaustible. Attempts to eliminate these indeterminancies of science merely replace science by a meaningless fiction. (....)

We should be glad to recognize that science has come into existence by mental endowments akin to those in which all hopes of excellence are rooted and that science rests ultimately on such intangible powers of our  mind.

Wednesday, February 12, 2014

The Creative Imagination -- by Michael Polanyi

"The Creative Imagination" by Michael Polanyi [PSYCHOLOGICAL ISSUES (1969) 6: 59-91] explores the role of intuition and imagination in the growth of scientific knowledge.  Due to the richness of the material, we have decided to devote two successive posts to the article.  Polanyi (1891-1976) had first hand knowledge of the scientific process: he was an esteemed physical Chemist turned philosopher of science.  He proposes here in the first part that scientific knowledge like ordinary perception depends on an internal integration of a variety of clues, many we may not be aware of. We focus on the object and only have subsidiary awareness of the clues that determine our perception; because the integration occurs internally, he calls this "personal knowledge".  In ordinary perception, this depends on the development of a coherence among our various senses.  In a similar vein in scientific endeavor, like a ball rolling down an incline, we are guided by the slope of greater coherence leading to an experience of deeper meaning.   The second part of the essay considers how the standards on which this coherence is based can change in the context of scientific work.

Polyani’s own statement in the article provides the best bridge between his view of the nature of scientific knowledge and spirituality. “ Science is based on clues that have a bearing on reality. These clues are not fully specifiable; nor is the process of integration which connects them fully definable; and the future manifestations of the reality indicated by this coherence are inexhaustible. These three indeterminacies defeat any attempt at a strict theory of scientific validity and offer space for the powers of the imagination and intuition.”  

An earlier version of the article was given as a lecture at Wesleyan University in 1965 and is available online. 

…[N]either imagination nor intuition are deemed rational ways of making discoveries. They are excluded from the logic of scientific discovery, which can deal then only with the verification or refutation of ideas after they have turned up as possible contributions to science. (....)

However…[n]o scientific discovery can be strictly verified, or even proved to be probable. (....)

There is in fact no sharp division between science in the making and science in the textbook. The vision which guided the scientist to success lives on in his discovery and is shared by those who recognize it. It is reflected in the confidence they place in the reality of that which has been discovered  and in the way in which they sense the depth and fruitfulness of a discovery.  (....)

...[T]eachers in philosophy are likely to raise their eyebrows at such a vague emotional description of scientific discovery. (....)

[Yet] Copernicus discovered the solar system by signs which convinced him. But these signs convinced  few  others.  For  the  Copernican  system  was  far  more complicated than that of Ptolemy: it was a veritable jungle of ad hoc assumptions. (....) He did not stop to consider how many assumptions he had to make in formulating his system, nor how many difficulties he ignored in doing so. Since his vision showed him an outline of reality, he ignored all its complications and unanswered  questions. 

(....) In spite of its vagueness and its extravagances, his vision was shared by great scientists like Kepler and Galileo. Admittedly, their discoveries bore out the reality of the Copernican system, but they could make these discoveries only because they already believed in the reality of that system.                         

We can see here what is meant by attributing reality to a scientific discovery. It is to believe that it refers to no chance configuration of things, but to a persistent connection of certain features, a connection which, being real, will yet manifest itself in numberless ways, inexhaustibly. It is to believe that it is there, existing independently of us, and that for that reason its consequences can never be fully predicted.

Our knowledge of reality has, then, an essentially indeterminate content: it deserves to be called a vision. (….)  

This vision, the vision of a hidden reality, which guides a scientist in his quest, is a dynamic force. At the end of the quest the vision is becalmed in the contemplation of the reality revealed by a discovery; but the vision is renewed and becomes dynamic again in other scientists and guides them to new discoveries. I shall now try to show how both the dynamic and the static phases of a scientific vision are due to the strength of the imagination guided by intuition. 

(....) I have pursued this problem for many years by considering science as an extension of ordinary perception. When I look at my hand and move it about, it would keep changing its shape, its size, and its color but for my power of seeing the joint meaning of a host of rapidly changing clues, and seeing that this joint meaning remains unchanged.  I recognize a real object before me from my joint awareness of the clues which bear upon it. (....)

We can recognize here two kinds of awareness. We are obviously aware of the object we are looking at, but are aware also--in a much less positive way--of a hundred different clues which we integrate to the sight of the object. When integrating these clues, we are attending fully to the object while we are aware of the clues themselves without attending to them. We are aware of these clues only as pointing to the object we are looking at. I shall say that we have a subsidiary awareness of the clues in their bearing on the object to which we are focally attending.

While an object on which we are focusing our attention is always identifiable, the clues through which we are attending to the object may often be unspecifiable. (....) 

But it is a mistake to identify subsidiary awareness with unconscious or preconscious awareness, or with the Jamesian fringe of awareness. …[I]t can have any degree of consciousness so long as it functions as a clue to the object of our focal attention. (....)

If science is a manner of perceiving things in nature, we might find the prototype of scientific discovery in the way we solve a difficult perceptual problem. Take for example the way we learn to find our way about while wearing inverting spectacles. …[Y]ou feel completely lost and remain helpless for days on end. But if you persist...eventually [you] can even drive a car or climb rocks with the spectacles on. (....)

The inverted image has been reconnected to other sensory clues, to touch and sound and weight. These all hang together with the image once more, and hence, though the image remains inverted, the subject can again find his way by it safely. A new way of seeing things rightly has been established. (….)

We see how the wearer of inverting spectacles reorganizes scrambled clues into a new coherence. He again sees objects, instead of meaningless impressions. (....) He has made sense out of chaos.

In science, I find the closest parallel to this perceptual achievement in the discovery of relativity. Einstein (Schilpp, 1949, p. 53) has told the story of how from the age of 16 he was obsessed by the following kind of speculations. Experiments with falling bodies were known to give the same results on board a ship in motion as on solid ground. But what would happen to the light which a lamp would emit on board a moving ship? Supposing the ship moved fast enough, would it overtake the beams of its own light, as a bullet overtakes its own sound by crossing the sonic barrier? Einstein thought that this was inconceivable, and, persisting in this assumption, he eventually succeeded in renewing the conceptions of space and time in a way which would make it inconceivable for the ship to overtake, however slightly, its own light rays. (....)

Relativity alone involves conceptual innovations as strange and paradoxical as those we make in righting an inverted vision. (....)

We generally see things as we do, because this establishes coherence within the context of our experience. So when Einstein extended his vision to the universe and included the case of a light source emitting a beam, he could make sense of what he then faced only by seeing it in such a way that the beam was never overtaken, however slightly, by its source. This is what he meant by saying that he knew intuitively that this was in fact the case. (....)

Science is based on clues that have a bearing on reality. These clues are not fully specifiable; nor is the process of integration which connects them fully definable; and the future manifestations of the reality indicated by this coherence are inexhaustible. These three indeterminacies defeat any attempt at a strict theory of scientific validity and offer space for the powers of the imagination and intuition.

This gives us a general idea of the way scientific knowledge is established at the end of an inquiry; it tells us how we judge that our result is coherent and real. But it does not show us where to start an inquiry, nor how we know, once we have started, which way to turn for a solution. (….) 

This·quest is guided throughout by feelings of a deepening coherence and these feelings have a fair chance of proving right. We may recognize here the powers of a dynamic intuition. (….)

Physics speaks of potential energy that is released when a weight slides down a slope. Our search for deeper coherence is likewise guided by a potentiality. We feel the slope toward deeper insight as we feel the direction in which a heavy weight is pulled along a steep incline. It is this dynamic intuition which guides the pursuit of discovery.(....)

But we must yet acknowledge further powers of intuition, without which inventors and scientists could neither rationally decide to choose a particular problem nor pursue any chosen problem successfully. …[T]hink of Einstein, when as a boy he came across the speculative dilemma of a light source pursuing its own ray. (....) His intuition told him that there must exist a principle which would assure the impossibility of observing absolute motion in any circumstances. Through years of sometimes despairing inquiry, he kept up his conviction that the discovery he was seeking was within his ultimate reach. (....)

The power by which such long-range assessments are made may be called a strategic intuition. (....) Without this kind of strategic intuition, he would waste his opportunities on wild goose chases and soon be out of a job. (....)  

It is a skill for guessing with a reasonable chance of guessing right…. The fact that this faculty often fails does not discredit it; a method for guessing 10% above average chance on roulette would be worth millions.

But to know what to look for does not lend us the power to find it. That power lies in the imagination.

I call all thoughts of things that are not present, or not yet present--or perhaps never to be present---acts of the imagination. (….) 

Take the example of learning to ride a bicycle. The imagination is fixed on this aim, but, our present capabilities being  insufficient,  its  execution  falls  behind.  By  straining  every nerve to close this gap, we gradually learn to keep our balance on a bicycle. (....)

This is the mechanism to which I ascribe the evocation of helpful clues by the scientist's imagination in the pursuit of an inquiry. But we have to remember here that scientific problems are not definite tasks. The scientist knows his aim only in broad terms and must rely on his sense of deepening coherence to guide him to discovery. He must keep his imagination fixed on these growing points and force his way to what lies hidden beyond them. We must see how this is done. (....)

No  quest  could  have  been  more indeterminate  in its aim than Einstein's inquiry which led to the discovery of relativity. Yet he has told how during all the years of his inquiry, "there was a feeling of direction, of going straight towards something definite. Of course," he said, "it is very hard to express that feeling in words; but it was definitely so, and  clearly to be distinguished from later thoughts about the rational form of the solution." We meet here the integration of still largely unspecifiable elements into a gradually narrowing context, the coherence of  which  has not yet become  explicit.(....)

Friday, November 15, 2013

On the Lighter Side: Richard Dawkins on The Daily Show

Richard Dawkins, an evolutionary biologist and author of THE GOD DELUSIONand more recently, AN APPETITE FOR WONDER: THE MAKING OF A SCIENTIST, is very critical of religion, perhaps overstating the case. Jon Stewart, the well-known host of THE DAILY SHOW, holds his feet to the fire. Dawkins insists that religion entails faith without evidence; he warns that followers are “seduced to do bad things” because they believe blindly in its doctrines. Later in the interview Stewart asks: “isn’t the job of a scientist to have faith that there’s something out there that we don’t understand?” Dawkins counters that religion and science differ because science involves faith that is based on evidence. In a past post Carl Sagan bridges the two by calling science "informed worship," evoking a more mystical attitude towards exploring our place in the world. But we have to ask further what "informed" means in this context. For example, a dialogue recounted on the blog between Dawkins and Francis Collins, former head of the DNA project and author of THE LANGUAGE OF GOD: A SCIENTIST PRESENTS EVIDENCE FOR BELIEFpoints out how differently the same evidence can be interpreted. (Our next post will delve deeper into the nature of evidence, and how the standards of evidence are established.)

Saturday, June 29, 2013

Mindfulness meditation training alters cortical representations of interoceptive attention

Mindfulness training helps stabilize experience by increasing awareness of the body as well as reducing unproductive mental elaboration of painful situations. In their paper, Farb et al. consider the role of the insula in the beneficial effects of mindfulness training. The posterior portion of the insula seems to serve as the primary interoceptive cortex, which registers internal bodily sensation. The anterior insula has an important role in determining whether attention is directed internally towards the body or externally towards the world. The paper shows that only 8 weeks of mindfulness training helps makes internal sensation more a part of the trainees habitual attentional stance.  It does this, the data suggests, in part by increasing the functional connectivity between different parts of the insula.

In many places we have used text passages out of order to support the narrative flow. For references, please refer to the original paper: Norman A.S. Farb et al. Mindfulness meditation training alters cortical representations of interoceptive attention, Soc Cogn Affect Neurosci (2013) 8 (1): 15-26. Extracted with permission from Oxford University Press.

This post, like the last one, resonates in an interesting way with Thomas Metzinger’s article on out of body experiences, in which one senses one’s own body more from an external perspective.  


IA= Internal Attention= breathe
EA= External Attention= suppress or maintain attention on something external
ROI = Region of Interest
MT = Mindfulness Training
MBSR = Mindfulness-Based Stress Reduction
PPI= psychophysiological interaction = functional connectivity
DMPFC = Dorsomedial prefrontal cortex


[I]nteroception involves sensation of the body itself, integrating visceral afferents associated with internal systems such as digestion, circulation, proprioception and respiration. ... [T]he posterior insula may constitute a primary interoceptive region, the anterior insula appears to integrate internal and external signals, regulating the direction of external attention both in constructive biases such as empathy and maladaptive biases such as addiction. ...While there are strong anatomical connections between the insula’s posterior interoceptive regions and its anterior zones, it is likely that the anterior regions are also heavily influenced by attention to external stimuli. Critically, the dominance of IA [Internal Attention] or EA [External Attention] in promoting anterior insula activity may be influenced by the attentional habits of the individuals being investigated...

The propagation of interoceptive signals from the posterior to anterior insula makes it an intriguing candidate mechanism for investigating training-related plasticity in interoceptive representation. Behaviorally, training appears to improve interoceptive accuracy for tasks such as heartbeat detection, suggesting possible neuroplasticity in an interoceptive representation network.

[W]e used functional magnetic resonance imaging (fMRI) to examine the effects of MT on the cortical representation of IA. We contrasted an untrained, waitlisted control group against individuals who had recently completed the 8 week MBSR training program. To measure IA recruitment, neural activity associated with breath monitoring was contrasted against two visual EA tasks, controlling for the common attentional requirements of maintaining sensory awareness and suppressing distraction. Using this paradigm, we were able to evaluate whether the representation of IA, including its specific propagation through the insula, was altered as a function of MT.
The MBSR course introduced participants to the practice of moment-to-moment, non-judgmental awareness through an 8 week program. Participants attended weekly group sessions introducing them to formal mediation practices, gentle yoga and education on stress responses and management. In addition to group meetings, on non-class days participants were asked to practice yoga and/or meditation for ~ 40min a day with the assistance of guided meditation CDs....

The formal meditation practices included breath monitoring, body scans (the progressive direction of attention to different parts of the body) and diffuse direction of attention to sounds, thoughts, feelings and bodily sensations.
Participants were trained on three experimental tasks, breath monitoring (‘Breathe’), cognitive suppression (‘Suppress’) and working memory maintenance (‘Maintain’) prior to fMRI data acquisition. For the Breathe task, participants were asked to attend to all sensory aspects of their breath (i.e. in the nose, throat, chest and diaphragm), without intentionally altering their respiratory rhythm and with their eyes open. In the event of mind-wandering, participants were asked to calmly return their attention to the breath. For the Suppress task, participants were asked to read foveally presented words while inhibiting any cognitive or emotional response, keeping their minds blank while attending to the word stimulus. For the Maintain task, participants were asked to press a key whenever a word was repeated in a visually presented sequence (a ‘1-back’ task).


Eight gray matter regions of interest (ROI) were selected according to the anatomical divisions of the insular gyri, ranging from the anterior accessory gyrus, through the short and long gyri of the middle insular, and into the short and long gyri of the posterior insula. To index primary interoceptive cortex, we identified a right posterior insula region related to variations in respiratory rate between task blocks. Referred to as the 'interoceptive seed' in the present study, we observed in prior work (Farb et al., 2012) that this posterior insula region was uniquely associated with variability in respiratory rate during IA, and this association was significantly stronger during IA than during EA. 

This interoceptive seed region was also strongly responsive to IA [breath] over EA [suppress or maintain] in both [meditation trained (MT) and untrained groups]... (Figure 4a), serving as a common region wherein attention modulates the representation of the interoceptive signal.  

Figure 4a

We used the interoceptive seed to examine group differences in condition independent 

[i.e. attention independent] and dependent PPI [psychophysiological interaction or] functional connectivity.  Independent of attention conditions, MT was associated with higher functional connectivity between the interoceptive seed and the right middle putamen, extending into the short gyrus of the anterior insula, [as indicated in] Figure 4b.  

Figure 4b

Condition-dependent connectivity also observed across groups in the ...posterior insula just rostral to the primary interoceptive seed, with higher connectivity in IA relative to EA. Subsequent analysis...suggested that the untrained group elevated insula connectivity to match condition-independent connectivity levels observed within the MT groups Figure 4c.  

Figure 4c [Note: Red represents internal attention; Blue represents external attention]

Thus while untrained participants were able to voluntarily invoke IA to promote connectivity of interoceptive signal from the primary interoceptive cortex towards more anterior sensory intergration regions, MT participants appeared to possess this increased connectivity regardless of task. Such a finding is consistent with a...goal of MBSR practices, to provide individuals with a consistent ‘on-line’ representation of body awareness even in the face of exogenously cued stressors, weakening conceptual knowledge with competing knowledge of constantly changing interoceptive sensations.

[Moreover] In whole brain analysis, the DMPFC [dorsomedial prefrontal cortex] demonstrated a unique interaction between group and attention.  DMPFC activation has been related to the deployment of focal attention, acting as an index of of executive processes that are present both during both effortful task-related concentration and during unintentional mind-wandering. Reduced IA related activity [was observed] in the MT but not the untrained group. (Data not shown).

Following MT, the DMPFC demonstrated IA-specific negative connectivity to primary interoceptive cortex in the posterior insula Figure 5.  [a shows whole brain analysis and b shows the variation in this negativity from region to region of the insula.]  

Figure 5
VAC, ventral accessory gyrus; VS, ventral short gyrus; PL, posterior long gyrus; 
AL, anterior long gyrus; PS, posterior short gyrus; MS, middle short gyrus; 
AS, anterior short gyrus; AC, accessory gyrus.
The present findings suggest an important role by which DMPFC facilitates MT effects, promoting reduced conceptual cortical activity and enhanced interoceptive connectivity.  DMPFC deactivation could therefore be one neural mechanism of attentional control enhancing interoceptive representation following MT.

MT was also associated with modulation of interoceptive signal amplitude.  While the primary interoceptive region did not demonstrate increased 1A-related recruitment in the MT Group, MBSR practice compliance was associated with increased attentional modulation of posterior insula cortex, consistent with experience dependent modulation of primary interoceptive cortex.  Figure 6 b.

Fig. 6

Additionally ...MT enhanced interoceptive representation in adjacent anterior insular cortex, a region more responsive to towards exteroception than than interoception prior to training.  [Data not shown]

Thus, participation in the in the MBSR program appeared to facilitate interoceptive integration across the MT group, regardless of practice compliance, consistent with an intention to integrate interoceptive information into present moment awareness.  However only through daily practice was the tone of the primary insular representation enhanced... 

[Conclusion]: The present study investigated whether IA practice through MT resulted in functional plasticity in interoceptive representation cortex. We were ... able to demonstrate two novel mechanisms by which MT may modulate the neural propagation of interoceptive signal from the posterior insula during IA: (i) MT may promote greater functional connectivity between the posterior insula and anterior insula gyri, leading to greater anterior insula activation and (ii) MT may simultaneously reduce DMPFC recruitment and strengthen negative DMPFC/insular connectivity. 

Friday, April 5, 2013

"Lectures on Mysticism" from The Varieties of Religious Experience -- by William James

We are pleased to excerpt William James’ lectures on mysticism from his book THE VARIETIES OF RELIGIOUS EXPERIENCE: A STUDY IN HUMAN NATURE. The original lectures are a delight to read. We can capture but a fraction of their spirit here, however we hope this post will compel you to read the original. James (1842-1910) was well-known as a philosopher, psychologist, and physiologist. He was an astute observer of experience, as well as an incisive thinker. He is often thought of as the father of modern psychology. Certain passages below resonate intriguingly with Thomas Metzinger’s “Out-of-body experiences as the origin of the concept of a “Soul’” excerpted previously.  

William James

One may say truly, I think, that personal religious experience has its root and centre in mystical states of consciousness. ... How do we part off mystical states from other states? ... [I] propose to you four marks which, when an experience has them, may justify us in calling it mystical... .

1 Ineffability. ...The subject of it immediately says that it defies expression… . [I]ts quality must be directly experienced… . [M]ystical states are more like states of feeling than like states of intellect. No one can make clear to another who has never had a certain feeling, in what the quality or worth of it consists.

2. Noetic quality. -- Although so similar to states of feeling, mystical states seem to those who experience them to be also states of knowledge. They are states of insight into depths of truth unplumbed by the discursive intellect. ... [A]s a rule they carry with them a curious sense of authority for after-time.

3. Transiency. -- Mystical states cannot be sustained for long. ...Often, when faded, their quality can but imperfectly be reproduced in memory; but when they recur it is recognized; and from one recurrence to another it is susceptible of continuous development in what is felt as inner richness and importance.

4. Passivity. -- Although the oncoming of mystical states may be facilitated by preliminary voluntary operations, as by fixing the attention, or going through certain bodily performances, or in other ways…; yet when the characteristic sort of consciousness once has set in, the mystic feels as if his own will were in abeyance, and indeed sometimes as if he were grasped and held by a superior power.  … Some memory of their content always remains, and a profound sense of their importance. They modify the inner life of the subject between the times of their recurrence.

Our next step should be to gain acquaintance with some typical examples. … [P]henomena are best understood when placed within their series, studied in their germ and in their over-ripe decay... .

The simplest rudiment of mystical experience would seem to be that deepened sense of the significance of a maxim or formula which occasionally sweeps over one. ... Most of us can remember the strangely moving power of passages in certain poems read when we were young, irrational doorways as they were through which the mystery of fact, the wildness and the pang of life, stole into our hearts and thrilled them. ... We are alive or dead to the eternal inner message of the arts according as we have kept or lost this mystical susceptibility.

A more pronounced step forward on the mystical ladder is found in an extremely frequent phenomenon, that sudden feeling, namely, which sometimes sweeps over us, of having "been here before,"

As Tennyson writes:
Moreover, something is or seems
That touches me with mystic gleams,
Like glimpses of forgotten dreams --
"Of something felt, like something here;
Of something done, I know not where;
Such as no language may declare.
A much more extreme state of mystical consciousness is described by J. A. Symonds; and probably more persons than we suspect could give parallels to it from their own experience.
It consisted in a gradual but swiftly progressive obliteration of space, time, sensation, and the multitudinous factors of experience which seem to qualify what we are pleased to call our Self. In proportion as these conditions of ordinary consciousness were subtracted, the sense of an underlying or essential consciousness acquired intensity. At last nothing remained but a pure, absolute, abstract Self. The universe became without form and void of content. But Self persisted, formidable in its vivid keenness, feeling the most poignant doubt about reality, ready, as it seemed, to find existence break as breaks a bubble round about it.
The next step into mystical states carries us into a realm that public opinion and ethical philosophy have long since branded as pathological, though private practice and certain lyric strains of poetry seem still to bear witness to its ideality. I refer to the consciousness produced by intoxicants and anaesthetic, especially by alcohol. The sway of alcohol over mankind is unquestionably due to its power to stimulate the mystical faculties of human nature, usually crushed to earth by the cold facts and dry criticisms of the sober hour. Sobriety diminishes, discriminates, and says no; drunkenness expands, unites, and says yes. It is in fact the great exciter of the Yes function in man. It brings its votary from the chill periphery of things to the radiant core. It makes him for the moment one with truth. Not through mere perversity do men run after it. To the poor and the unlettered it stands in the place of symphony concerts and of literature; and it is part of the deeper mystery and tragedy of life that whiffs and gleams of something that we immediately recognize as excellent should be vouchsafed to so many of us only in the fleeting earlier phases of what in its totality is so degrading a poisoning. The drunken consciousness is one bit of the mystic consciousness, and our total opinion of it must find its place in our opinion of that larger whole....

Certain aspects of nature seem to have a peculiar power of awakening…mystical moods. Most of the striking cases which I have collected have occurred out of doors. ... I take this from Starbuck's manuscript collection:
[T]he consciousness of God's nearness came to me sometimes. I say God, to describe what is indescribable. ... I felt myself one with the grass, the trees, birds, insects, everything in Nature. I exulted in the mere fact of existence, of being a part of it all -- the drizzling rain, the shadows of the clouds, the tree-trunks, and so on. 
Here is a similar record from the memoirs of that interesting German idealist, Malwida von Meysenbug:
I was alone upon the seashore as all these thoughts flowed over me, liberating and reconciling; and now again, as once before in distant days in the Alps of Dauphine, I was impelled to kneel down, this time before the illimitable ocean, symbol of the Infinite. I felt that I prayed as I had never prayed before, and knew now what prayer really is: to return from the solitude of individuation into the consciousness of unity with all that is, to kneel down as one that passes away, and to rise up as one imperishable. 
[F]rom the Autobiography of J. Trev[a]or.
For nearly an hour I walked along the road to the 'Cat and Fiddle,' and then returned. On the way back, suddenly, without warning, I felt that I was in Heaven -- an inward state of peace and joy and assurance indescribably intense, accompanied with a sense of being bathed in a warm glow of light, as though the external condition had brought about the internal effect -- a feeling of having passed beyond the body, though the scene around me stood out more clearly and as if nearer to me than before, by reason of the illumination in the midst of which I seemed to be placed. 
The writer adds...
The spiritual life...justifies itself to those who live it; but what can we say to those who do not understand? ... This, at least, we can say, that it is a life whose experiences are proved real to their possessor, because they remain with him when brought closest into contact with the objective realities of life. Dreams cannot stand this test. 
We have now seen enough of this cosmic or mystic consciousness, as it comes sporadically. We must next pass to its methodical cultivation as an element of the religious life. Hindus, Buddhists, Mohammedans, and Christians all have cultivated it methodically.

In India, training in mystical insight has been known from time immemorial under the name of yoga. Yoga means the experimental union of the individual with the divine. It is based on persevering exercise; and the diet, posture, breathing, intellectual concentration, and moral discipline vary slightly in the different systems which teach it.

[Quoting] from VIVEKANANDA, Raja Yoga, London, 1896.
All the different steps in yoga are intended to bring us scientifically to the superconscious state or Samadhi. ... Just as unconscious work is beneath consciousness, so there is another work which is above consciousness, and which, also, is not accompanied with the feeling of egoism. ... There is no feeling of I, and yet the mind works, desireless, free from restlessness, objectless, bodiless. 
The Buddhists used the word "samâdhi" as well as the Hindus; but "dhyâna" is their special word for higher states of contemplation. There seem to be four stages recognized in dhyâna. The first stage comes through concentration of the mind upon one point. It excludes desire, but not discernment or judgment: it is still intellectual. In the second stage the intellectual functions drop off, and the satisfied sense of unity remains. In the third stage the satisfaction departs, and indifference begins, along with memory a self-consciousness.  [Refer to the text for the fourth stage!]

In the Christian church there have always been mystics. ... The basis of the system is "orison" or meditation, the methodical elevation of the soul towards God. ...The first thing to be aimed at in orison is the mind's detachment from outer sensations, for these interfere with its concentration upon ideal things.

[Saint Teresa writes]
In the orison of union the soul is fully awake as regards God, but wholly asleep as regards things of this world and in respect of herself. During the short time the union lasts, she is as it were deprived of every feeling.... God establishes himself in the interior of this soul in such a way, that when she returns to herself, it is wholly impossible for her to doubt that she has been in God, and God in her. ...The deliciousness of some of these states seems to be beyond anything known in ordinary consciousness. I confess that it is all a mystery in which I am lost. 

The Ecstasy of Saint Teresa by Bernini, Basilica of Santa Maria della Vittoria, Rome

Do mystical states establish the truth of those theological affections in which the saintly life has its root? ... In spite of their repudiation of articulate self-description, mystical states in general assert a pretty distinct theoretic drift. ... We pass into mystical states from out of ordinary consciousness as from a less into a more, as from a smallness into a vastness, and at the same time as from an unrest to a rest. We feel them as reconciling, unifying states. They appeal to the yes-function more than to the no-function in us. In them the unlimited absorbs the limit. ...  In mystic states we both become one with the Absolute and we become aware of our oneness. In Hinduism, in Neoplatonism, in Sufism, in Christian mysticism, in Whitmanism, we find the same recurring note, so that there is about mystical utterances an eternal unanimity which ought to make a critic stop and think... .

Our own more "rational" beliefs are based on evidence exactly similar in nature to that which mystics quote for theirs. Our senses, namely, have assured us of certain states of fact; but mystical experiences are as direct perceptions of fact for those who have them as any sensations ever were for us. The records show that even though the five senses be in abeyance in them, they are absolutely sensational in their epistemological quality, if I may be pardoned the barbarous expression -- that is, they are face to face presentations of what seems immediately to exist.

But more remains to be told, for religious mysticism is only one half of mysticism. The other half has no accumulated traditions except those which the text-books on insanity supply. Open any one of these and you will find abundant cases in which "mystical ideas" are cited as characteristic symptoms of enfeebled or deluded states of mind. In delusional insanity, paranoia, as they sometimes call it, we may have a diabolical mysticism, a sort of religious mysticism turned upside down. ... It is evident that from the point of view of their psychological mechanism, the classic mysticism and these lower mysticisms spring from the same mental level, from that great subliminal or transmarginal region of which science is beginning to admit the existence, but of which so little is really known. ... Its value must be ascertained by empirical methods, so long as we are not mystics ourselves.