The 5 Impurities block the
Lucidity of Mind:

The Blessed Buddha once
said:
There are five impurities of gold impaired by which it becomes neither pliant,
nor wieldy, it lacks radiance, is weak
and easily broken and cannot be formed...
What are these five impurities? They are: Iron, copper, tin, lead and silver.
But if the gold has been purified from these five impurities, then it will
indeed
be pliant and wieldy, radiant and firm, and can be formed well. Whatever
kind
of jewellery one wishes to make from it, be it a diadem, earrings, a necklace
or
a golden chain, it will easily serve that purpose well.
Similarly, there are five impurities of the mind impaired by which the
mind is
neither pliant, nor wieldy, it lacks radiant lucidity and stability, and
cannot
concentrate well upon the eradication of the
mental fermentations
(āsava).
What are these five impurities? They are:
1: Sense-Desire,
2:
Evil-Will,
3:
Lethargy and Laziness,
4:
Restlessness and Regret,
5:
Doubt and Uncertainty...
But if the mind is freed of these five mental
hindrances, then it will be plastic,
flexible, and wieldy, will be of radiant lucidity and firm, calm stability,
and will
concentrate well upon the elimination of the
mental fermentations. Whatever
supra-human state realizable by these higher mental abilities one may
pursue,
one will in each case be able to directly experience it, as an eye-witness...

Buddha said: The mind is naturally
radiant,
but veiled
by mental hindrances!
More on these 5 Mental Hindrances
(Nīvaranas):
https://What-Buddha-Said.net/drops/II/The_5_Mental_Hindrances.htm
https://What-Buddha-Said.net/drops/II/Feeding_the_Hindrances.htm
https://What-Buddha-Said.net/drops/II/Starving_the_Hindrances.htm
https://What-Buddha-Said.net/drops/II/How_5_Become_10.htm
https://What-Buddha-Said.net/drops/II/The_Canal.htm
https://What-Buddha-Said.net/drops/II/Naturally_Radiant.htm
https://What-Buddha-Said.net/drops/IV/Suitable_Substitution.htm
https://What-Buddha-Said.net/Canon/Sutta/AN/AN.I.3-4.htm
https://What-Buddha-Said.net/Canon/Sutta/AN/AN.I.3-4c.htm
https://What-Buddha-Said.net/drops/II/The_Fire_of_Sense-Desire.htm
https://What-Buddha-Said.net/drops/II/Colourful_but_Muddy.htm
https://What-Buddha-Said.net/drops/II/Anger_and_Irritation.htm
https://What-Buddha-Said.net/drops/II/Lethargy_and_Laziness.htm
https://What-Buddha-Said.net/drops/II/Restlessness_and_Regret.htm
https://What-Buddha-Said.net/drops/II/Doubt_and_Uncertainty.htm
https://What-Buddha-Said.net/drops/II/The_Causes_of_Ignorance.htm

Comments:
The
4 mental fermentations are wrong, false
and hidden assumptions associated
with:
1: Sense-desire (kāmāsava). Ex: "Sensing is only
and always pleasant.
Pain exists not!"
2: Desiring becoming into new existence (bhavāsava): Ex: "All life
is good, Death exists not!"
3: Wrong views (ditthāsava): Ex: "I am better, know better
and what
I think is thus never wrong!"
4: Ignorance (avijjāsava): Ex: "Suffering, craving, ending craving
and the Noble Way exists not!"
For Details on the 3 Mental Fermentations
(āsava)
please see:
https://What-Buddha-Said.net/library/DPPN/wtb/a/aasava.htm
https://What-Buddha-Said.net/drops/The_Proximate_Cause.htm
https://What-Buddha-Said.net/drops/II/Cause_of_Ignorance.htm
https://What-Buddha-Said.net/drops/II/The_Three_Fermentations.htm
https://What-Buddha-Said.net/drops/III/Freed_from_Fermentation.htm


Consciousness is a
wave-phenomena just like electromagnetic radiation.
Source
(edited extract):
The Numerical Sayings of the Buddha.
Anguttara Nikāya.
The Book of Fives 23: Four deeds of Merit... [III: 16-7]