In time, every principle that has been derived from external experience will be disproved and become obsolete. For as mankind progresses man's knowledge of the world changes; and, in the end, the known world is the only existing 'world'.
On the other hand, whatever is known from a central experience ('out of the inner light', as the mystics put it) will remain irrefutable, provided that it has been seen purely and truly.
Therefore the harshest reproach that even Lao Zi's worst opponent, the cultural prophet Han Yu, could make was that the sage lived at the bottom of a well and did not see the world: but what he did see from there no man can refute. In this context it is useful to note that it is not the psychologically conditioned, accidental ego which is important to Lao Zi.
The ego is the seat of illusion and danger. Lao Zi is concerned with the Self (the 'pure "I'" which belongs to man-as-man). In order to progress from the empirical ego to this supra-individual entity a great deal of abstraction from everything accidental and distinctively individual is required.
This penetration into the supra-individual sphere appears to be a decrease, while the business of research with its accumulation of individual, separate and specific insights appears as an increase. The most important thing is that the heart should become empty: only then can it comprehend the great truths.
Lao Zi continually praises the empty heart as the ideal condition for true knowledge as well as for action. To understand this correctly we must not forget that for the Chinese the word 'heart' means something quite different from what it means in Christian-influenced, European thought.
To a European the chief associations are with 'courage', or 'feelings' and this colors and determines its meaning.
For the Chinese, however, the word 'heart' primarily refers to one of the five senses; more specifically, it refers to that complex of senses which mediates most directly with the outside world, and which is commonly called 'sensation'. It follows from this that the heart is also the source of desire for external things.
For Lao Zi all involvement with the empirical world through the senses and desires is perilous; it hinders true cognition because it is the source of illusion. The way to penetrate to the truth consists in 'closing the gates' through which these illusionary impressions enter our inner world.
It is immediately obvious, then that all positive knowledge takes a back seat. In fact, Lao Zi dismisses all 'knowledge' and 'cognition' as insufficient.
One might think this would inevitably lead to a denial of the world. But this is not his intention at all. Instead his approach is based on the view that where appearances end, the true, hidden being -- eternal, and superior to the fleeting changes of sensory illusion -- comes into focus all the more clearly and purely.
Lao Zi does not seek 'cognition' but 'seeing', inner 'enlightenment'. It is, however, made very clear in a number of places that this 'seeing' has nothing to do with ascetic visions: on the contrary, Lao Zi absolutely approves of the care for one's 'body' and 'bones' necessary for one's physical well-being.
This inner 'enlightenment' leads quite of its own accord to simplicity, the most beautiful symbol of which is the child who has not yet been hurled about in the whirlpool of desires. The human being thus forms a continuous unity which returns into itself, and whose activity unfolds spontaneously.
Within this unity, the expression of every principle or attribute is immediately complemented by its opposite, which is posited together with and by it, just as every wave in the sea is accompanied by a trough.
This harmony of balance is not even disturbed by birth or death: for it brings with it eternal life reaching beyond death. At this point Lao Zi's consideration of the problem of cognition leads him almost imperceptibly to a metaphysical principle: DE or Life. For according to Lao Zi, Life is nothing other than this spontaneously active essence of man, identical, in the final analysis, with the foundation of the world.
Spontaneity of activity is of the greatest importance in this respect: for this spontaneity is the secret of Life of the highest order. From the point of view of the individual, however, this very spontaneity appears as something negative. For the individual 'holds back'.
The individual does not live itself, but 'lets itself be lived', it is 'being lived'.