One of Berkeley’s most distinctive theses is the claim that the world that appears to us in perception and experiment constitutes a “divine language,” an address from God: “There is a certain analogy, constancy, and uniformity in the phaenomena or appearances of nature, which are a foundation for general rules: and these are a grammar for the understanding of nature, or that series of effects in the visible world, whereby we are enabled to foresee what will come to pass, in the natural course of things. Plotinus observes, in his third Ennead, that the art of presaging is in some sort the reading of natural letters denoting order” (Siris §252). Think of this as an answer to Hume’s objections to induction avant la lettre: we know we can interpret natural events as rationally ordered, as intelligible; we know that this ordering isn’t a function of human conventions; therefore, there must be an orderer, an intelligence manifest to us in and through the world’s appearances. This is God, of course; Berkeley’s argument is strikingly similar to Aquinas’s fifth way toward God, from natural teleology (cf. ST 1.2.3).
Costica Bradatan (in his marvelous The Other Bishop Berkeley) has shown that Berkeley’s divine-language thesis fits comfortably within the patristic and scholastic “liber naturae” tradition, which saw the world as a “book” given to illumine and edify the faithful; but a closer analogue, albeit surely influenced as well by that same tradition, is Shakespeare. In his As You Like It, Duke Senior enjoins his companions-in-exile: “This our life, exempt from public haunt, / Finds tongues in trees, books in the running brooks, / Sermons in stones, and good in everything” (II.1.562-66). Like the Duke, the good Bishop sees the whole world as a conversation had between the LORD and those whom he calls friends.