To understand how karma is empty it's better to understand why
ALL feelings, sensations, and thoughts, are empty. Empty does not
mean non-existent, it means insubstantial, empty of a solid,
inherent, independent existence.
Emptiness means everything, including karma, is a dependently
originated appearance -- due to certain conditions, karmic
consequences 'appear' but are without substantial inherent
existence. When new karma arise they are also dependently
originated appearance -- they are momentary instants of
consciousness dependently arisen.
As I wrote recently (slightly edited):
...
The short answer is whatever feelings are present, it is just a
momentary, conditioned appearance. There is no substantiality, or
essence, or any tangible, permanent, inherent existence to it.
Whatever we feel and experience, we somehow give it more
'solidity' and 'reality' than it actually has, much like treating a
mirage/appearance for a solid reality. And we become attached to
it.
When the condition is not, then the
feeling/sensations/experience isn't. When condition is there then
the feelings are there but it is simply part of the transient flow
of phenomenality, like a mirage, but with no tangible existence on
its own
Like a thirsty person chasing the mirage of water in a desert,
we human beings chase after feelings, experiences, 'things'. We are
unable to see that they are insubstantial, momentary 'instants' of
manifestation/consciousness without any concrete permanent inherent
existence. It has no inherent characteristics, qualities, shapes,
or forms -- only a momentary appearance. Our thoughts and feelings
and emotions are insubstantial too, due to certain conditions the
*appearances* of these emotions arise, but after a while when the
condition subsides they also disappear. It's not constant and is
part of the everchanging flow of consciousness, it's not always
there, and there is no tangible independent existence apart from
those conditions that give rise to the appearances/mirage/etc.
So even though they vividly appear, like the mirage of water,
they are not 'real' (tangible). While they are not real, they are
still the vivid display of our luminous clarity/pure awareness,
like the bright mirror having the capacity to reflect all
appearances. Our Buddha-Nature is just this,
luminous-emptiness.
On the insubstantiality of our experiences, Buddha taught:
"....Now suppose that in the autumn — when it's raining in fat,
heavy drops — a water bubble were to appear & disappear on the
water, and a man with good eyesight were to see it, observe it,
& appropriately examine it. To him — seeing it, observing it,
& appropriately examining it — it would appear empty, void,
without substance: for what substance would there be in a water
bubble? In the same way, a monk sees, observes, & appropriately
examines any feeling that is past, future, or present; internal or
external; blatant or subtle; common or sublime; far or near. To him
— seeing it, observing it, & appropriately examining it — it
would appear empty, void, without substance: for what substance
would there be in feeling?
"Now suppose that in the last month of the hot season a mirage were
shimmering, and a man with good eyesight were to see it, observe
it, & appropriately examine it. To him — seeing it, observing
it, & appropriately examining it — it would appear empty, void,
without substance: for what substance would there be in a mirage?
In the same way, a monk sees, observes, & appropriately
examines any perception that is past, future, or present; internal
or external; blatant or subtle; common or sublime; far or near. To
him — seeing it, observing it, & appropriately examining it —
it would appear empty, void, without substance: for what substance
would there be in perception...
This applies not only to our thoughts and emotions but to our
experience of the "physical world". For example, we experience the
physical universe as having some solid existence "out there". For
example when we see a tree, we immediately label it and have
preconceived notions about a tree, and we treat that image as being
an accurate representation not only of our immediate experience but
rather, of "things" having an independent existence or inherent
characteristic.
When we look at lets say a red flower, we think that there is a
truly a "red flower" out there with a particular shape, size,
colour, etc... i.e. there are inherent attributes to an external
object. But reality is, there is no objective reality apart from
the perception itself. For example: the perception of "red" is due
to certain biological and karmic conditioning of humans alone,
other animals like dogs etc cannot perceive the same way as we do.
In fact they cannot perceive colours. So how can we say that there
is an inherent "red" flower out there? Furthermore, if we are given
a “quantum eyesight” to look into the atomic structure, there is
similarly no attribute “redness” anywhere found, only almost
complete space/void with no perceivable shapes and forms. Whatever
appearances are dependently arisen, and hence is empty of any
inherent existence or fixed attributes, shapes, form, or “redness”
-- merely luminous yet empty, mere Appearances without
inherent/objective existence. What gives rise to the differences of
colours and experiences in each of us? Dependent arising... hence
empty of inherent existence. This is the nature of all phenomena.
Whatever we see, hear, etc, is empty of an "objective" or
"inherent" existence out there -- and our vision is completely
conditioned arising, having no independent, inherent existence of
its own (i.e. is empty).
As you've seen, there is no ‘The Flowerness’ seen by a dog, an
insect or us, or beings from other realms (which really may have a
completely different mode of perception). 'The Flowerness' is an
illusion that does not stay even for a moment, merely an aggregate
of causes and conditions. Analogous to the example of ‘flowerness’,
there is no ‘selfness’ serving as a separate observer either --
awareness is not a background witness. Rather, the entire whole of
the moment of manifestation is our pristine awareness; lucidly
clear, yet empty of inherent existence. This is the way of ‘seeing’
the one as many, the observer and the observed are one and the
same. This is also the meaning of formlessness and
attributelessness of our nature. But "formless" and "empty" does
not mean nothingness or void, as Heart Sutra said, Emptiness is
Form -- Forms are vividly luminous but empty of inherent
existence....
