You say: 'But if the idea of Grasping is not applicable to the living Arahat when, for example, he is taking food,—then I am confronted with a genuine difficulty. In other words, if one cannot say that when the Arahat is taking food, he is (not) taking hold in some fashion or other, then I am faced with the difficulty of finding or comprehending what basically is the difference between life-action and other action, as of physical inanimate things'.
The first remark that must be made is that anyone who is a puthujjana ought to find himself confronted with a difficulty when he considers the Buddha's Teaching. The reason for this is quite simply that when a puthujjana does come to understand the Buddha's Teaching he thereby ceases to be a puthujjana. The second remark (which, however, will only displace your difficulty from one point to another, and not remove it) is that all conscious action is intentional (i.e., purposive, teleological). This is as true for the arahat as it is for the puthujjana. The puthujjana has sankhār'upādānakkhandha and the arahat has sankhārakkhandha. Sankhāra, in the context of the pañcakkhandhā, has been defined by the Buddha (in Khandha Samy. 56: iii,60) as cetanā or intention.
Intentionality as a necessary characteristic of all consciousness is well recognized by the phenomenological (or existential) school of philosophy (have a look at the article 'Phenomenology' in the Encyclopaedia Britannica), and though the subject is not particularly easy it presents no inherent difficulties. But in order to understand the nature of intention it is absolutely necessary to return to the notion of 'entities', and to consider the structure of their temporary persistence, which is 'Invariance under Transformation'. This principle occurs in quantum mechanics and in relativity theory, and in the Suttas it makes its appearance as uppādo paññāyati; vayo paññāyati; thitassa aññathattam paññāyati, three characteristics that apply to all the pañcakkhandhā (see Khandha Samy. 37: iii,38). Intentionality is the essential difference between life-action and action of inanimate things.
But now this difficulty arises. What, precisely, is upādāna (grasping, or as I prefer, holding) if it is not synonymous with cetanā (intention)? This, and not any other, is the fundamental question raised by the Buddha's Teaching; and it is extremely difficult to see the answer (though it can be stated without difficulty). The answer is, essentially, that all notions of subjectivity, of the existence of a subject (to whom objects are present), all notions of 'I' and 'mine', are upādāna. Can there, then, be intentional conscious action—such as eating food—without the notion 'It is I who am acting, who am eating this food'? The answer is, Yes. The arahat intentionally eats food, but the eating is quite unaccompanied by any thought of a subject who is eating the food. For all non-arahats such thoughts (in varying degrees, of course) do arise. The arahat remains an individual (i.e. distinct from other individuals) but is no longer a person (i.e. a somebody, a self, a subject). This is not—as you might perhaps be tempted to think—a distinction without a difference. It is a genuine distinction, a very difficult distinction, but a distinction that must be made.
On the question of anicca/dukkha/anattā it is necessary, I am afraid, to be dogmatic. The aniccatā or impermanence spoken of by the Buddha in the context of this triad is by no means simply the impermanence that everybody can see around him at any moment of his life; it is something very much more subtle. The puthujjana, it must be stated definitely, does not have aniccasaññā, does not have dukkhasaññā, does not have anattasaññā. These three things stand and fall together, and nobody who still has attavādupādāna (i.e. nobody short of the sotāpanna) perceives aniccatā in the essential sense of the term.
For this reason I consider that any 'appreciation of Buddhism by nuclear physicists' on the grounds of similarity of views about aniccatā to be a misconception. It is worth noting that Oppenheimer's dictum, which threatens to become celebrated, is based on a misunderstanding. The impossibility of making a definite assertion about an electron has nothing to do with the impossibility of making a definite assertion about 'self'. The electron, in quantum theory, is defined in terms of probabilities, and a definite assertion about what is essentially indefinite (or rather, about an 'indefiniteness') cannot be made. But attā is not an indefiniteness; it is a deception, and a deception (a mirage, for example) can be as definite as you please—the only thing is, that it is not what one takes it for. To make any assertion, positive or negative, about attā is to accept the false coin at its face value. If you will re-read the Vacchagotta Sutta (Avyākata Samy. 8: iv,395-7), you will see that the Buddha refrains both from asserting and from denying the existence of attā for this very reason. (In this connection, your implication that the Buddha asserted that there is no self requires modification. What the Buddha said was 'sabbe dhammā anattā'—no thing is self—, which is not quite the same. 'Sabbe dhammā anattā' means 'if you look for a self you will not find one', which means 'self is a mirage, a deception'. It does not mean that the mirage, as such, does not exist.)
I should perhaps say, in order to forestall possible misunderstandings, that I consider Dahlke's statement, 'Consciousness and its supporting points are not opposites, but transitions, one the form of development of the other, in which sankhāras represent that transition-moment in which thinking as vedanā and saññā, in the glow of friction, is on the point of breaking out into viññāna', to be wholly mistaken. This is not 'paticca-sam' at all. Perhaps you will have already gathered that I should disagree with this from my last letter.
[37.1] a difficult distinction: As his letters to the Ven. Ñānamoli Thera make clear, this distinction was the Ven. Ñānavīra Thera's last major insight prior to his attainment of sotāpatti. Although certainly this particular perception need not be pivotal for all who achieve the Path, that it was so for him is one reason for the strong emphasis the author lays on this point in the Notes as well as in various letters. [Back to text]
If we ask, for instance, whether the position of the electron remains the same, we must say 'no'; if we ask whether the electron's position changes with time, we must say 'no'; if we ask whether the electron is at rest, we must say 'no'; if we ask whether it is in motion, we must say 'no'. The Buddha has given such answers when interrogated as to the conditions of a man's self after death; but they are not familiar answers for the tradition of seventeenth and eighteenth-century science. (Science and the Common Understanding, pp. 42-3, quoted on pp. 49-50 of Mr. Wettimuny's book.) [Back to text]