Thus, having arrived at the very ground of the world - that is, where the cosmic laws might be expected to reveal themselves directly - the scientist finds himself in the remarkable situation of only being able to determine accurately either the position of an observed object and not its state of motion, or its state of motion and not its position. The law he seeks, however, requires that both should be known at the same time. Nor is this situation due to the imperfection of the scientific apparatus employed, but to its very perfection, so that it appears to arise from the nature of the foundation of the world - in so far, at least, as modern science is bound to conceive it.