"The question of whether there is an external physical reality independent of sentient beings' consciousness and mind has been extensively discussed by Buddhist thinkers. Naturally, there are divergent views on this issue among the various philosophical schools of thought. One such school [Cittamatra] asserts that there is no external reality, not even external objects, and that the material world we perceive is in essence merely a projection of our minds. From many points of view, this conclusion is rather extreme. Philosophically, and for that matter conceptually, it seems more coherent to maintain a position that accepts the reality not only of the subjective world of the mind, but also of the external objects of the physical world."
I agree with the Dalai Lama's position here. Acceptance of the reality of external objects is not a denial of dependent origination.
I accept the existence
of 'external objects'. But they are 'external' relative to what? Where is this division between 'external' and 'internal' established if not in the mind? According to sunyavada, objects are not non-existent, but their reality is imputed and conventional rather than inherent. And as I have observed a number of times already, physics is still unable to establish an ultimate entity on the basis of which we can claim that objects are grounded in some fundamental material reality.
So what does it mean to say that objects are 'empty of inherent existence'? Why is this such an important idea in Mahayana Buddhism? I know elsewhere in that same book (Universe in a Single Atom) you will find H.H. spelling out exactly how scientific materialism attributes 'inherent existence' to material entities and why he differs with it.
I think you are grasping external objects to establish your sense of reality. That is OK as far as it goes, but it is characteristic of a certain cultural mentality. That is not a personal slight by any means as we are all wrestling with these issues.
I am going on vacation with my wife and have promised her I won't be sitting in the motel room posting to the Forum, so I am off for a few days. In parting, one more salient quotation, from a non-Buddhist writer, albeit one who was greatly influenced by Buddhism, namely E.F. Schumacher, of 'Small is Beautiful' fame. This is from a lecture of his on 'The Insufficiency of Liberalism':
The first great leap was made when man moved from Stage One of primitive religiosity to Stage Two of scientific realism. This is the stage modern man tends to be at. Then some people become dissatisfied with scientific realism, perceiving its deficiencies, and realize that there is something beyond fact and science. Such people progress to a higher plane of development which he called Stage Three. The problem was that Stage One and Stage Three looked exactly the same to those in Stage Two. Consequently, those in Stage Three are seen as having had some sort of relapse into childish nonsense. Only those in Stage Three, who have been through Stage Two, can understand the difference between Stage One and Stage Three.
Learn to do good, refrain from evil, purify the mind ~ this is the teaching of the Buddhas