Rope of sand

If any flaw can be detected in this reasoning, its author will be the first to admit that these Institutes are, from beginning to end, a mere rope of sand; but if no flaw can be detected in it, he begs to crave for them the acknowledgment that they are a chain of adamant.

Out of his ideas he may weave cunning theories, beautiful ideals; but he is working with ropes of sand. At the slightest stress, the last least bit of cohesion flits away, and each idea flies apart from its fellows, while all clamor that he do this thing, or think this thing, in the ancient and time-honored way. He is only a clay-born; so he bends his neck. He knows further that the clay-born are a pitiful, pitiless majority, and that he may do nothing which they do not do.