This should be the same as Yogachara, but I am familiar with the Chinese version (Weishi), so I will start this in the East Asian forum.
This is basically the only sticking point I've come to in this very clear tradition. It's probably a very simple fix.
In explaining how all dharmas are dependent upon consciousness, and are subjective feeling rather than objective reality, that they are basically non-existent, it is explained in this way; let's take for example, eye-consciousness and form.
Even science proves that the eye can only see color, and that color is created subjectively when light rays reflect into the eye and the eye-consciousness translates it into color. But every being may have a different translation because it is completely subjective and changes appearance according to their karma- such as those animals which see black and white.
Based on this it is said that we never see an object itself, only color which is a subjective creation of our eye-consciousness. Also feeling the object or hearing the object by knocking on it... all ways in which we can know an object is in fact subjective and not at all objective.
Feeling hard and soft, hot and cold is also our subjective feeling. Feeling is not the object itself, just like color is not the object itself. When we knock on an object, air vibrates our eardrum and if the ear-consciousness is activated it will translate that vibration into sound. So sound is also created by our consciousness, and not existing objectively. Nothing is wrong with our ears when we are sleeping, and people are talking next to us. Consciousness is just resting, so there is no sound.
So we can never say we have experienced an object itself
Following this logic it is said that all dharmas are empty, non-existent, because they are subjective experiences which are obviously unreal. My only problem with this is that light rays reflect off an object's surface into our eyes and is then translated into color. Color is not the object, and light is not the object. But although we can't see light itself, if it is reflecting off of something and our eye-consciousness translates it differently, does that not prove that there is something external to our consciousness that the light reflects off of, even though we have no way of experiencing it itself?
Same with sound. When I knock on a desk air is moved, the eardrum is vibrated and sound is created subjectively. Sound is not the desk, air is not the desk, the hard feeling of knocking the desk is also not the desk. But do these not prove there is something there, even though we have no way to experience it directly through our consciousness? Can't we apply logic here and know there is some objective reality, just that we can't directly know it? Perhaps that is the karma of a human being.
In Weishi Philosophy we are asked to use logic to see that since there is delusion, even though all such distinctions are unreal, then there is mind capable of delusion, just that we cannot use mind to turn around and know itself. It only knows objects of its cognition. So the saying is; "the eye can't see itself, the mind can't know itself". Of course then we establish that since there is no object, there can be no subject.
Well, I apply this same type of logic to the fact that there are light rays reflecting off the surface of something and into our eyes where eye-consciousness translates it into color and we see "form", even though light isn't the object, and color isn't the object itself. We can't experience the object through our consciousness, but using the same logic we can say that it exists external to our consciousness. We can't "know" that, but we can see using such logic.
Again, as the rest of this tradition is very clear, I'm sure the riddle to this perceived discrepancy is quite clear as well. Anyone?