When thinking about the Supreme Principle one needs to know what is meant by principle in the first place. To stick to its real meaning is even more pressing considering the fact that in the postmodern world, ”principles are always and everywhere lacking, … the word being commonly applied more or less regardlessly to things that are least worthy of it, and sometimes even to things that imply the negation of all true principle.” René Guénon (Shaykh `Abd Al Wahid Yahya) [fn1a]

“Modern civilization appears in history as a real anomaly: Among all those we know, it is the only one which developed in a purely materialistic direction and the only one which does not rely on any principle of higher order.” René Guénon (Shaykh `Abd Al Wahid Yahya) [fn1b]

The principle is The First Cause, the Absolute Eternal:

2.1: (or) a fundamental truth or proposition that serves as the foundation for a system of belief or behavior or for a chain of reasoning.
•  (or) a rule or belief governing one's personal behavior:
(such as when saying “he was struggling to be true to his own principles.”)
•  (or) morally correct behavior and attitudes: ( “a man of principle.”)

2.2: a fundamental source or basis of something:
(such as when saying “the first principle of all things is water.”)
•  a fundamental quality or attribute determining the nature of something; an essence. [fn2]

Specifically in this context the Principle #1 refers to
•  the Supreme Principle,
•  the Origin of all causes,
•  the Unity without beginning,
•  the Eternal Absolute,
•  that which is beyond manifestation as well as beyond non-manifestation,
•  that which is beyond all comprehension,
•  the ’non-dual.’ [fn8]
(see ch.4 below)

These definitions might themselves remind the reader as to what will be the outcome for someone who has no principle, or is not aware of any which is the same, and therefore not holding fast to a (or really: to The) principle.
A little story pointing towards the consequences of ignoring and dismissing the principle:

The Story Of The Man Who Did Not Hold Fast To The (One True) Principle (Bec. He Was Ignorant Of It):
There was once a man wandering through the earth his whole life. While learning many trades and ways of this life, he was always searching for 'the thing' (this is how he called what he imagined to be his principle). In his early life he would roam the coasts, and when he did not find it there, he crossed countless rivers and valleys in his later years. Finally when he was old and with great effort, he would turn towards the forests and the mountains - still searching for the thing - for he knew it had to be somewhere. But when asked about it, he could not even say what this 'thing' was, for which he had struggled all his life.
Finally, before he would leave this world, he knew: his 'thing' was not the Supreme Principle!

The problem is then how can we limited human creatures come to know anything permanent, true and real, or how can we “blind and ignorant shadows of existence, discern the difference between Being and nothingness?” [fn3]

The sun rises in the East, and when we look at the Eastern concept of the First or Supreme Principle we realize that it is somehow different from the Western one. The expression of the Supreme Principle is clearer in Eastern traditions, especially in Islam. - - - . . . - -
This is not really surprising as it reflects the most important, universal concept there is: that of a Source, or a Beginning (بدَايَة) of everything there is and of everything there will be and the idea of returning to it. This in the sense of Allah being the First & the Last, 'the place' of Origin (مَبْدَع) and 'the place' of Return (مَعَاد).

The second observation to make in this respect is that this term of 'Principle' forbids one from falling into the anthropomorphic error (i.e. of having human characteristics), meaning the far-reaching and disastrous error of attributing human qualities to the Divine Being, or to bring down the Divine to a sort-of-human level. This is of course what the Islamic tradition has always protected its followers, the Muslims, from happening.

Then how would the concept of a principle be described in a Far Eastern context? For this we quote from the foreword on a Muslim Chinese scholarly work, the “Great Learning of the Pure and Real” by Wang Tai-yü[fn4]. In the foreword to the English translation Tu Weiming states that:

“Tawhid demands that all of existence be governed by a single, supreme Reality - which the Chinese `ulama had no objection to calling by the Neo-Confucian term ’Principle’ (li). Everything comes from this One, Real Principle, and everything returns to it…”

The Islamic tradition declared this Principle as utterly “transcendent and ineffable [i.e. too great or extreme to be expressed or described in words], where personal and anthropomorphic language is totally inappropriate.”
Therefore as by comparison “the twin ideas of transcendence and immanence, or the assertion of Allah's incomparability (tanzīh) and his similarity (tashbīh), are the yin and yang of Islamic theology.”[fn4]

When René Guénon - Shaykh Abd Al Wahid Yahya [fn5] - reformulated in the modern West 1924 the concept of Tradition [fn6], he showed that it refers to the 'Principle', by which he means the Origin of all & everything, the Unity without beginning, the Absolute Eternal, meaning that which is beyond both the manifested as well as the non-manifested, therefore beyond comprehension, and 'non-dual'. [fn7]

The 'Principle' then is the name given to the 'First Source', which is totally unconditioned, out of any definition, the Unique without a second, of which human language is incapable to reveal its true nature. René Guénon continues to state that this supreme Principle, can only be designated ”to be without duality”,
beyond any and every determination (even beyond the determination of 'being', which is the first determination).

Any positive designation or attribution, would implicitly restrict its totality, as is required by its infinity, comprising in itself all possibilities, which is necessarily 'the absolute totality'. [fn7]

A traditional society [in the sense used here] is one that is based on principles of a higher order, i.e. where the intellectual (NB: wider meaning of this word![fn8]) order governs all other levels of society, may they be the sciences, or the social institutions. ”This way is the return to the Tradition or the return to the principles really one and the same thing.” [fn7]

In Islam this is essential to grasp this principle and to live by it, for the Principle is God or Allah,
from which everything is derived. So the Muslim is he (or she) who expresses this 1st principle and reality by witnessing that:

*There is no God but the one God, and
**Muhammad is the Messenger of God.**
LAA ILAAHA ILLALLAH MUHAMMAD UR RASULULLAH
Therefore none is worthy of worship except Allah
while Muhammad is the Messenger of Allah ﷺ.