Prof. Muni Mahendra Kumar
From the foregoing discussion it follows that Eddington believes that there exist real objects (or objective events) in the external world, which function as the common causes of the sensations in different consciousnesses. According to him, the objective structure of the external world is reproduced first in our senses and then in our mind. The original structure is distorted twice-firstly in its passage through the sensory equipment and secondly during its passage through the intellectual equipment.[1] Consequently, the structure of sensations in consciousness would always differ from the original structure of the external world. It is 'the structure of sensations in consciousness' that we know and not 'the original structure of the external world'.[2] In other words, knowledge of the external world is limited to the structural knowledge (of sensations) and physical science is the study of the structural knowledge.[3] The knowledge acquired by the methods of physical science is called "Physical Knowledge"[4] and the world described by the physical knowledge is called "physical universe."[5] Thus, physical universe is built up of the structures of 'the sensations in our consciousness' (which are the reproductions of the objective structures of the external world). The process of building up of physical universe is described by Eddington thus: "One sensation (divorced from knowledge already obtained by other sensations) tells us nothing: it does not even hint at anything outside the consciousness in which it occurs. The starting point of physical science is knowledge of the group-structure of a set of sensations in a consciousness. When these fragments of structure, contributed at various times and by various individuals, have been collected and represented according to the forms of thought that we have discussed, and when the gaps have been filled by an inferred structure depending on the regularities, discovered in the directly known portions, we obtain the structure known as the physical universe."[6]
Thus, Eddington distinguishes 'physical world' from 'external world'. The 'external world' is wholly objective whereas the 'physical world' is partly objective and partly subjective.[7] He does not distinguish between the 'physical world' and the 'world of physics' as he observes: "The physical universe is the world which physical knowledge is formulated to describe, and there is no difference between the physical universe and the universe of physics."[8]
In the case of visual sensation, the process of reproduction is repeated many times: "The structure of our visual sensation of a constellation is reproduced many times over in the external world-in a set of material objects, in light waves, on the retina, in optic nerves, in brain cells. The reproduction in actual sensation follows at the end of this sequence." (-Ibid., p.210).
