NATURE OF INTERPRETATION. 49 
that limit is not seeing, but imagining. And really it is tacitly 
conceded that this is so. For when a particularly ingenious 
theory which, we think, enables us to come into close quarters 
with a phenomenon is brought forward, our praise is not for 
the marvellousness of the mechanism discovered, but for the 
ingenuity of the brain which conceived it. We praise Mendel, 
not for the mechanism of segregation ; how could we? We 
have never seen it. We say, ‘‘ What intellect!” and not 
“What works!’ Moreover, it is easily proved that this is 
so, for if interpretation really meant a making out of works, 
there should be greater unanimity in the sphere of interpretation 
than in that of description, because the closer we can look, 
the more easily can we see. Thus, I think, we must admit that 
there is all the difference in the world between discovery of 
the mechanism of a human invention and the propounding of 
a theory to account for a mechanism of Nature. 
Inasmuch as our interpretation of Nature consists in in- 
creasing the length of the line E P by the length of the line E I, 
instead of shortening the line E P as in the case of our clock, 
it follows that there must always be a theoretical doubt 
concerning the correctness of our ultimate conclusions about 
Nature. So long as we stick to observation we are safe enough, 
but the moment we begin to explain things we fina ourselves 
on treacherous ground, and the most we can say about any bit : 
of Nature’s mechanism is, “ This is how +t might work, and 
possibly how it does.” 
It may be objected, of course, that although we never see 
into Nature because the mechanism of phenomena is invisible 
to us, yet we can deduce the mechanism from its effects with 
considerable accuracy, and the proof of our accuracy lies in 
the fact that the application of our deductions to untried 
circumstances has often proved satisfactory in every way. 
Thus, Adams and Leverrier independent!y predicted the 
existence of a new planet, and on pointing their telescopes to 
that particular part of the heavens where the planet was 
calculated to be, they were rewarded, as we all know, by the 
discovery of Neptune. Graham, reflecting on the consequences 
of the theory of the polarization of light waves, predicted the 
occurrence of certain optical effects within a crystal, and these 
7 6(7)14 
